I ■' I, ^ ' ' , ' ; ' '' ' ■ ' ; ' ■ ' ' ''j 'I V \ THE TEXAS JOURNAL OF SCIENCE A Quarterly Review of Science T. N. Camptell; Editor CLAUDE C. ALBRITTON, JR., JOHN W. FORSYTH, GUY T. McBRIDE, JR. and JOHN G. SINCLAIR, Associate Editors VOL. V 3504Si L/brarT Erin ted in San Marcos, Texas, U. S. A. Eublished by THE TEXAS ACADEMY OF SCIENCE 1953 SOS. 73 .TaTs*)- le TEXAS PUBUSHED PARTERLYtyTHETEXASACAOEMYOFSCIENCE ■ 01. V March 30,1953 NO. 1 1 For twenty-one years, SEl has specialized in sub-surface studies of the domestic oil provinces . from Canada to the Gulf. Numerous innovations in instrumentation, inter¬ pretation, and field technique have kept SEl in the fore¬ front. For example, in difficult areas, SEl has been a pioneer in the use of patterns of multiple shot holes and geophone arrays Your exploration program is in capable hands at SEl. TECHNIQUE lEIIMK EXPLORATION# INCORPORATED HOUSTON, TEXAS 1007 SOUTH SHEPHERD your guarantee of Extra quality HUMBLE MOTOR FUEL * Esso Uniflo Csso Extra gasoline & motor oil ATLAS TIRES & lATTillES RElSEiUaCH THimX MEWER EMDS» We’ve never made a rock bit that completely satisfied us . . . and we never will, although we have made millions of bits. One improvement has invariably led to others, opening new frontiers for research and progress. As a result, record breaking bits of not too many years ago have become today’s museum pieces. Through the years Hughes Tool Company’s expenditures in research and engineering to improve the performance of its bits and advance rotary drilling have run into millions of dollars. Currently, these expenditures are at a rate of more than $ 1 ,5 00,000 per year. This continuing research enables Hughes to keep pace with the constantly changing needs of a fast moving drilling industry. Progress dictates that we can never be satisfied with any improvement of the moment. EXECUTIVE COUNCIL, 1953 President: D. B. Calvin, The University of Texas, Medical Bratich Executive Vice President: Joseph P. Harris, Jr., Southern Methodist University Secretary-Treasurer: Gladys H. Baird, Huntsville Representative to A. A. A. S.: C. M. Pomerat, The University of Texas, Medical Branch Vice President, Sec. I, Physical Sciences: D. F. Leipper, The A. & M. College of Texas Vice President, Sec. II, Biological Sciences: E. L. Miller, Stephen F. Austin State College Vice President, Sec. Ill, Social Sciences: Edith L. Robinson, Texas State College for Women Vice President, Sec. IV, Earth Sciences: S. E. Clabaugh, The University of Texas Vice President, Sec. V, Conservation: R. P. Wagner, The University of Texas Collegiate Academy: Sister Joseph Marie Armer, Incarnate Word College Junior Academy: Greta Oppe, Ball High School, Galveston BOARD OF DIRECTORS President: D. B. Calvin, The University of Texas, Medical Branch Executive Vice President: Joseph P. Harris, Jr., Southern Methodist University Secretary-Treasurer: Gladys H. Baird, Huntsville Immediate Past President: Willis G. Hewatt, Texas Christian University Elected Director: Don O. Baird, Sam Houston State Teachers College Elected Director: E. E, Rosaire, Consulting Geophysicist, Dallas Elected Director: W. R. Woolrich, The University of Texas BOARD OF DEVELOPMENT W. R. Woolrich, The University of Texas L. W. Blau, Humble Oil & Refining Company, Houston Everette DeGolyer, DeGolyer and McNaughton, Dallas J. Brian Eby, Consulting Geologist, Houston O. S. Petty, Petty Geophysical Company, San Antonio Allan Shivers, Governor of Texas MEMBERSHIP COMMITTEE Chairman: A. A. L. Mathews, University of Houston CONSERVATION COUNCIL President: John G. Sinclair, The University of Texas, Medical Branch PURPOSE: To encourage and coordinate research in Texas by bringing scientific workers together and by publishing the results of their investigations : to advise individuals and the government on scientific matters ; to assemble and maintain library and museum facilities. ORGANIZATION : The activities of the Academy embrace all scientific fields. In the Senior Academy, there are five Sections : Physical. Biological. Social, and Geological Sciences, and Conservation. Regionally, the Senior Academy is divided into three branches : East Texas, South Texas and West Texas. The Collegiate Academy promotes the organization of science clubs in colleges and universities. The Junior Academy encourages scientific activities in secondary schools. MEMBERSHIP: “Any person engaged in scientific work, or interested in the promotion of science” is eligible to membership. PUBLICATIONS: The Proceedings and Transactions of the Academy are incorporated in THE' TEXAS JOURNAL OF SCIENCE, published quarterly. MEETINGS: State-wide annual meetings are held in the fall, and regional meetings in the spring of each year. DUES: Annual members, $5 per year. Life members, at least $100.00 in one payment. Sustaining Members, Mo per year. Patrons, at least $500.00 in one payment. Life members and patrons are exempt from dues, receive all publications, and participate as active members. SUBSCRIPTION RATES: Members $5 per year. Single copies $1.25 each. Volume V, No. 1, March, 195.3 Published Quarterly at San .Marcos, Texas (Entered as Second Class Matter, at Postoffice, San Marcos, Texas, March 21, 1949) Tke Texas J ournal of Science Published Quarterly by The Texas Academy of Science EDITOR T. N. Campbell Department of Anthropology The University of Texas Austin, Texas ASSOCIATE EDITORS Sewell H. Hopkins Department of Biology The A & M College of Texas College Station, Texas Claude C. Albritton, Jr. Department of Geology Southern Methodist University Dallas, Texas Guy T. McBride, Jr. Department of Chemistry The Rice Institute Elouston, Texas John G. Sinclair Department of Anatomy The University of Texas Medical Branch Galveston, Texas J. Brian Eby, Chairman John J. Andujar . Anton Berkman . L. W. Blau . C. C. Doak . John C. Godbey . Joseph P. Harris, Jr . W. G. Hewatt . H. A. Hodges . Clifford B. Jones . Ernest L. Kurth . John B. Loefer . E. L. Miller . C. M. Pomerat . E. E. Rosaire . H. J. Sawin . Aaron P. Seamster . C. M. Shigley . Cornelia Smith . Victor J. Smith . Otto O. Watts . Arthur W. Young . PUBLICATION BOARD . Consulting Geologist, Houston . Fort Worth Medical Laboratory . Texas Western College . Humble Oil & Refining Co., Houston . The A. & M. College of Texas . Southwestern University . Southern Methodist University . Texas Christian University . Pan American College . Texas Technological College . Southland Paper Mills, Inc., Lufkin . . . Southwest Foundation for Research and Education . Stephen F. Austin State College . The University of Texas, Medical Branch . Consulting Geophysicist, Dallas . University of Houston . Del Mar College . Dow Chemical Company, Freeport . Baylor University . Sul Ross College . Haidin-Simmons University . Texas Technological College ADVERTISING DIRECTOR Robert Lee Miller & Associates 1951 Richmond Houston 6, Texas Volume V No. 1 COVER PICTURE This picture was taken on the Art Baughman farm, Raymondville, Texas, which is in the Willacy-Hidalgo Soil Conservtion District. It shows contour rows filled with water after a heavy downpour. This water would have run off and been lost for future crop production without contour rows. There would also have been a great deal of erosion accompanying the loss of this amount of water. Photograph courtesy of Mr. Paul H. Walser, State Conservationist, United States Department of Agriculture Soil Conservation Service, Temple, Texas. Tke Texas Journal of Science CONTENTS FOR MARCH, 1953 Looking Ahead in Soil Conservation. Paul H. Walser 5 Factors Affecting Trait Frequencies in Human Populations. C. P. Oliver . 9 Factors Affecting Gene Exchange Between Populations in the Peromyscus maniculatus Group. W. Frank Blair . 17 The Nicotinic Acid Requirement of Drosophila melanogaster and its Relationship to the Brown Eye Pigment. Bernard Wortman and Robert P. Wagner . 34 An Experimental Approach to the Enigma of Tumor Susceptibility and Growth Based upon Individual Metabolic Patterns Roy. B. Mefford, Jr., and John B. Loefer . 38 Notes on the Cell Wall of Higher Plants. Richard B. Rypma . 49 Establishment and Utilization of Bulbous Bluegrass, Poa bulbosa L., in North Texas Subseres. I. Taxonomic Description and Developmental Morphology. A. W. Roach and J. K. G. Silvey . 59 The Thiamine Content of Self-Selected Diets of College Women As Related to the Enrichment of Cereals. Florence I. Scoular and Ada Ruth Rankin . 64 Ternary Liquid System: Phenol-Water-n-Propyl Alcohol. F. F. Mikus and S. E. Carson . 70 Reflection of Centimeter Radio Waves from Ground and Water Surfaces. A. W. Straiton . 76 The Adsorption of Surface-active Reagents During Flow Through Porous Media. Turgut Y. Gulez and Harry H. Power . 85 Boundary Conditions in the Fourier Integral Formulation. W. F. Helwig . 102 Thorstein Veblen and Primitive Society. Murray E. Polakoff . 106 Keys to the Larvae of Texas Mosquitoes, With Notes on Recent Synonymy. IF The Genus Culex Linnaeus. Osmond P. Breland . 114 Arthropod-borne Diseases in Texas in 1950. R. B. Eads and R. D. Griffith . 120 Ectoparasites Occurring on Mammals in the Vicinity of Fort Hood, Texas. Robert A. Hedeen . 125 Fertility Status of Cultivated Soils in Wichita County, Texas. William O. Trogdon . 130 LOOKING AHEAD IN SOIL CONSERVATION PAUL H. WALSER U. S. Department of Agriculture Soil Conservation Service Temple, Texas Twenty years ago soil conservation was scarcely more than a theory. There were those, of course, who realized that erosion was a menace, but many of our people did not at that time suspect the magnitude of the danger. A few investigators, however, most of them at experiment stations, had begun to foresee the preventive and the corrective treatment that our agri¬ cultural lands would need to keep them producing for the millions and millions of Americans who must draw life from the soil. Today we look upon soil conservation as a national need and we accept it as a sound way of conducting the business of farming. We have made a good start in a relatively short time. A part, and a good part, of the job has been done, and the farmers and ranch operators who have taken the lead in this foresighted way of using land are reaping benefits that can be seen, weighed and copied by others. Today a large segment of the people in this nation see and understand the need for soil conservation. It is being discussed and taught in schools and in public gatherings not directly concerned with the use and treatment of land. Colleges have introduced courses in soil conservation and the number of young men who are interesting themselves in the subject as a life work is increasing year by year. The progress we have made has come in the last 10 years, and most of our real achievements from a very practical standpoint have occurred during the last five years. The rate at which soil and water conservation practices are being applied on farm and ranch land is more rapid now than at any previous time, and there is every reason to believe that the work will go ahead at a faster and faster rate. Therefore, I feel that all of us who are concerned directly and profes¬ sionally with this program can look ahead with optimism. There are several reasons. Organized soil conservation districts now cover well over 90 per cent of the farm and ranch lands of Texas. The governing bodies of these districts have progressed through the trial and error stage and now, equipped with experience and a practical understanding of their problems, are going ahead at quickening pace with the job for which they were conceived. These boards of district supervisors are exercising the leadership which was and is expected of them. They are making good use of the facilities that the Soil Conserva¬ tion Service, the Agricultural Conservation Program and the other agencies and organizations have to offer. They are helping to spread a public con¬ sciousness of the need for conservation and a new appreciation of land and its characteristics among all groups. S APR 6 1953 6 The Texas Journal of Science 1953, No. 1 March Technical know-how has made rapid strides in the last decade and now has reached the point at which it can perform greater-than-ever service for the landowner and operator. This know-how represents as skilled and exper¬ ienced a technical force as you will find in American agriculture today. It is provided for the most part by agencies of state and federal governments; and of course as State Conservationist of the Soil Conservation Service I must offer the Soil Conservation Service, as the leader in this field. This Service is the agency which has been given the assignment by the Department of Agri¬ culture to devote all its skills and energies to the assistance of American farmers and ranchers in their problems of soil and water conservation. The devotion of this agency to its work has paid off to the lasting benefit of the men who own and operate the soil. Its search for effective methods and means of attacking the problems of erosion and soil depletion has resulted in a vast contribution to the nation’s agriculture. This work will continue and on a vaster scale. There are technical problems yet to be solved, but I hold they are not without solution. The same faith and determination which has led to other advancement will certainly lead to more. Inasmuch as our potential in accomplishments for the future is founded largely upon what we have done in the immediate past, I can point with considerable pride to the advancement we have made in the use of legumes and grasses in the conservation program. Using legumes and grasses in con¬ servation cropping systems is a basic practice in the protection and improve¬ ment of agricultural land. The use of this practice is spreading as never before. It will continue to spread. The use of grasses and legumes in permanent tame pasture is another phase of our program that has been receiving increasing attention. Livestock owners have increased production far beyond expectations in many instances. This practice will spread rapidly, and we shall find new combinations that will be even more productive than those we are making use of now. The seeding of perennial grasses on land not suited to cultivation has won the attention of thousands of landowners in the last 10 years. The use of grass in soil conservation has been an extremely useful and effective tool. It is a tool that has paid good dividends in restoring damaged land to a stable, productive state. Seed production and seed harvest, both of grasses and legumes, have become new and important phases of the seed industry. The rate at which this activity has been increasing indicates it is still far from a peak. Stubble mulching has proved itself an extremely effective practice in the conservation and improvement of soil. It, too, can be counted on to claim wider attention in years to come. Its usefulness in preventing erosion and in helping to maintain a high level of organic matter in the soil is highly respected. The few years just behind us have brought important advances in range conservation. This practice in soil conservation got off at first to a slow start, but its more recent rate of progress has been extremely rapid. It has won high esteem among ranchers the nation over. Its further acceptance as a way toward a sound grassland economy cannot be questioned. The importance of this progress in range conservation cannot be dis¬ missed lightly. Over half of the yearly forage for Texas livestock comes from native grass. Any substantial gain in the production of grass volume 1953, No. 1 March Looking Ahead in Soil Conservation 7 means a like gain in the production of livestock and livestock products. And that means greater income for the men who own and operate range lands. The invasion of waste trees and brush in the range country^ however, is a problem which has as yet no adequate answer. There are 80 to 90 million acres of these plants, all of them helping to retard or reduce grassland gains. The solution to this problem lies in the future, but 1 predict that it will be solved. Until we do solve it, however, mesquite v/ill spread at the rate of 3 00,000 acres a year, cedar at 2 5,000 acres, huisache 20,000 and sand sage¬ brush at 10,000. Control of this costly growth must be achieved through good range management, mechanical and chemical controls and through artificial range seeding. In woodland conservation our progress may have been less than we might reasonably have expected. However, this phase of our program is going ahead now at a greatly accelerated pace. In the Soil Conservation Service we now have recognized that in farm forestry, as in other phases of this pro¬ gram, the primary problem is the reluctance of people to accept this new concept in forestry management. We are now passing on to the farmer and other owners simple principles that they can readily use in managing wood¬ lands however small or large they may be. I foresee substantial gains in the near future in the conservation care of our woodlands. A growing interest in the future of water in the Southwest indicates, to me, that water needs will be met and that, when they are, soil and water conservation measures will play a big part. The problems of water are in¬ separable from those of soil and when we have solved the soil phase of the matter we also have solved the other. We have in Texas much land which needs only water and good treatment to make it abundantly productive. The conservation of supplies now available and the development of new sources lie ahead. The drainage of wet lands represents a broadening opportunity in this state. The cooperation of state and federal agencies is continually opening new outlets for excess water. Records of increased production from lands formerly too wet for successful cultivation have been most convincing. There is still much of it to be done. A heightening public interest in agricultural flood prevention should lead to more and more activity on this front. Some of the state’s most pro¬ ductive land lies in creek and river bottoms. Crop yields in too many in¬ stances are sporadic, with floodwaters making cultivation unprofitable or cutting production far below potentials. Therefore, the application of land treatment measures in creek watersheds with engineering measures to slow down runoff offers a promising future for the agriculture of Texas. Opera¬ tions already are under way in the Trinity and Middle Colorado watersheds. They are far enough along in Honey Creek above McKinney in the East Fork of the Trinity to furnish scon a real example of the effectiveness of this program. A closer working relationship with the Agricultural Conservation Pro¬ gram, a development of recent months, has paved the way for faster progress. This new relationship between two agencies striving toward the same goal means new convenience and better service for the farmer or rancher seeking help and more widely effective assistance by the working^ force in the field. 8 The Texas Journal of Science 1953, No. 1 March In a summary of the factors and conditions upon which I base a note of optimism for soil and water conservation in coming years, I believe there is one fundamental reason for our present encouraging rate of progress and our brightening opportunities for the future. This is the widening acceptance by the public of Nature’s unchanging and unchangeable plan for the sustenance of mankind and all other living creatures on the earth. Our problem in the use of land should never have been a difficult one— for man had only to observe and to copy in principle the ways of Nature. However, in departing from these principles which are Nature’s guide- posts, man has heaped trouble upon himself. In his search for food he has too often abused and neglected this life-sustaining resource. And he and his descendents have paid and they will always pay. In our program of soil and water conservation, we return to the simple procedures of Nature’s plan, using our endowment for the things to which it is suited and giving damaged land the treatment it needs to restore it in time to a state as near as possible to the original condition. This is the con¬ servation objective of the Department of Agriculture, stated in the recent memorandum which consolidated the efforts of the agencies involved. This new understanding of Nature’s pattern and the appreciation of this essential resource, the soil, is more and more apparent on every hand, not only among men and women who are concerned with the production of agricultural goods but among all groups, civic, commercial, religious or educational. Our children are developing this appreciation in classrooms, our business men are hearing about it and talking to others about its importance as a factor in good business. We even hear about it in our churches. And this is a fitting place for our people to learn this lesson, for the Bible is filled with references to the stewardship of land. We are inclined to think of this problem as applying only to our nation, but the need is even more desperate in some of the other countries of the world. And here we may look to further progress: for this new respect for the land and its limitations is spreading to every corner. We are on the threshold of a new era in agriculture, one in which the right use and appropriate treatment for land are unfailing guides to the perpetuation of mankind. FACTORS AFFECTING TRAIT FREQUENCIES IN HUMAN POPULATIONS^ C. P. OLIVER The University of Texas INTRODUCTION A better understanding of human relationships is resulting from the cooperative research of anthropologists, geneticists, and workers in other related fields. Some easily recognized and regularly occurring morphologi¬ cal variations have been used to divide human beings into a few racial groups. For finer divisions of the main groups investigators have sought other characteristics. With the aid of additional traits it has been possible to show relationships among groups of people which could not be recognized from earlier investigations. A characteristic which is ideal for the study of populations is one which recurs generation after generation and has a genetic basis. The fre¬ quency with which a hereditary trait occurs may vary over a period of gen¬ erations. Under ordinary circumstances, though, the change in trait fre¬ quency will be so slight that it is possible to repeat studies for comparative purposes. If an environmental agent causes a trait, studies of the charac¬ teristic in two generations may cause misinterpretations. The necessary environmental agent may exist in one generation, but not in the next, and thus result in striking variations in the trait frequency. INCREASED KNOWLEDGE ABOUT HEREDITARY TYPES The vascular system of man has made possible a number of useful genetic traits. Antigens associated with red blood cells can be identified with relative ease and blood types thereby determined. An investigator can repeat his own studies on antigens as well as use data collected by other workers with assurance that the blood typing can be relied upon. The genetic basis of several blood types is known. The history of the use which has been made of blood types in the study of population relationships shows the benefits to be derived from increasing our knowledge about human hereditary traits. Landsteiner in 1900 first dis¬ covered the four blood groups in man which are based on the presence or absence of antigens A and B. Within a few years investigators concluded that a person’s blood group is determined by a complex of genes. In 1924 Bernstein showed that the distribution of the blood groups are in agreement with results to be expected if a series of multiple alleles is involved. It became evident that distinct racial groups differed in frequencies of the four blood groups but that most races included some members in each of the four blood groups. Sub-populations in one race also differ in 1 Read at a symposium on "Population Genetics” at the annual meeting of the Texas Academy of Science, Austin, Texas, December 8, 1951. 9 10 The Texas Journal of Science 1953, No. 1 March relative frequencies of the blood groups and of the genes. In this country, for example, the frequency of the gene responsible for antigen B is higher in certain localities than in others. Within the past few years other antigens have been discovered in man. These are due to genes which are inherited independently of those responsible for the A-B types. A summary of the history of these discoveries has been given by Race (1951). All of the new types increase the possibility of a more complete understanding of population relationships. Combinations of the blood types lead to some complexities, as might be expected. For ex¬ ample, one blood type, the Lewis, was discovered to be closely associated with the ability of a person to secrete the A-B substances. Sub-groups of the ABO, MN, and Rh blood types have been discov¬ ered. These discoveries have helped investigators differentiate people where the broader phenotypes were not sufficient for that purpose. Australian aborigines and New Guinea natives were known to have similar gene fre¬ quencies as determined by studies of M-N blood types. After the sub¬ divisions MS, Ms, etc., became known in 1947, investigators showed that the two groups of people are markedly unlike for the presence and absence of the '^S” subdivision. Australian people do not have the MS type which is present in New Guineans. Subdivisions of the Rh-positive blood type have also become a tool which can be used to increase cur knowledge of diversity in gene frequency and blood types among some human groups. North Europeans and Africans south of the Sahara Desert differ in proportions of Rh-positive and Rh- negative members, but not in such a striking manner. A remarkable differ¬ ence in the alleles causing the Rh-positive type does exist. The Rh-positive Europeans have a very high frequency of Ri (also called R®’ or CDe). The Rh-positive people in Africa have a high frequence of the R® allele (cDe), a form of the gene occurring infrequently in Europeans. VARIED EXPRESSIONS OF HEREDITARY TRAITS Other genetic traits are needed for population studies. Many traits considered to be hereditary occur so infrequently that their value is ques¬ tionable. Some other traits which occur frequently enough to make them useful have other complications. The gene may not always be expressed (reduced penetrance) or the trait may not be the same in all persons hav¬ ing the gene (varied manifestation). Investigators who do not recognize these variations may report trait and gene frequencies as being different in two populations even though that is in error. DENTAL ANOMALIES All men have the same general dental pattern. The teeth are hard structures and can be observed easily in living and fossil men. If variations of teeth occurred frequently, they would be good characteristics to use in the study of national and sub-population diflferences. This would not be true for defects such as opalescent dentine or for the so-called "brown” teeth which wear down to the gums. Each of these traits has a dominant inheritance, but its frequency in a population is low. One dental anomaly, congenital absence of teeth, occurs with a fairly high frequency and may prove to be a useful trait in the study of sub¬ populations. The defect is not merely the failure of teeth to erupt. Certain teeth fail to erupt and the dental buds are lacking. 1953, No. 1 March Trait Frequencies in Human Populations 1 Any tooth may on occasion fail to develop, but the problem is simpli¬ fied by the fact that the anomaly is usually limited to only certain kinds of teeth. Approximately 2 5 percent of our people fail to develop one or more of the third molars. The next most frequently missing teeth are the second bicuspids, or premolars. Upper lateral (second) incisor teeth are involved about as frequently as the second bicuspids. Canine teeth are rarely missing unless a person has one of the diseases which affects teeth as well as other structures of the body. Among the patients of a dental clinic studied by Brekhus, Oliver and Montelius, 3 52 non-related persons were discovered who lacked one or more of their teeth. In all, 1189 teeth had failed to develop. The study did not include the third molar teeth unless some other condition caused the indi¬ vidual to be included as a subject. Nevertheless 2 82 of the absent teeth were third molars. There were 329 second bicuspids and 3 32 upper second incisor teeth missing or very abnormal in shape. Congenital absence of teeth is not a rare anomaly. In the report by Oliver, Brekhus and Montelius, 2.4 percent of 4000 subjects lacked one or more of the second bicuspid teeth, and 2.1 percent had involvement of the upper second incisor teeth. Second bicuspid teeth can be used for studies of trait differences only with difficulty. A deciduous tooth which has been retained may in some cases be mistaken for a permanent tooth. One such case occurred in our study. A young man became indignant because we asked him about his missing second bicuspid. He stated with emphasis that he had all 32 teeth and advised us to check oral radiographs which had been made if we would not accept his word. The radiographs showed that a deciduous tooth filled the space for a permanent tooth which would never develop. Upper second incisors are more easily studied. A layman can detect the absence or very abnormal shape of the tooth. The incisor teeth are frequently missing, the frequencies among different groups varying from one to 5.1 percent according to reports. The group differences may represent true population differences, but they may be closely linked with the varied mani¬ festations of the trait and the failure of workers to take into consideration these variations. Anomalies of the upper lateral incisor teeth range from slight decrease in size, though abnormal shape, to total absence of the teeth. A number of persons have twin or supernumerary second incisor teeth. It seems probable that one primary gene-pair is involved in the lateral incisor defect. Causes of the differences in degree of severity are as yet unknown. Variation in the trait sometimes causes asymmetrical expression in a person. Relatives with the trait also may differ in type of expression. The variations and their frequencies among 212 probands and 122 close relatives are shown in Table I. Probands who lacked both lateral incisors occurred most frequently (45.8% of probands). Another 10,8% has a pair of peg¬ shaped incisors. In 15.6% one tooth was absent, but the other was peg¬ shaped. All other probands had an anomaly on only one side, either one miss¬ ing (15.1%) or one peg-shaped (7.5%) or a supernumerary (5.2%). The various anomalies occurred in the affected' relatives in approximately the same proportions as in the probands. Comparisons of affected siblings and of affected parent-child combi¬ nations show that relatives tend to have the same degree of expression of the anomaly, but exceptions are often observed. In one sibship, three affected members had three varieties of the trait: both incisors absent in one; one 12 The Texas Journal of Science 1953, No. 1 March absent and one pegged in another; one peg-shaped and the other present in a third member. All of the affected children of the three siblings had the severest anomaly, or both sides lacking the second incisors. In another family, a father with both upper second incisor teeth peg-shaped produced three affected children; their traits were: both teeth absent in one; both peg-shaped in a second; and in the third child only one side affected and that being a peg-shaped tooth. Family histories show that parents lacking both incisor teeth may on occasion produce affected children with several gradations of the anomaly. The usefulness of the dental anomaly for comparative studies of human populations is decreased by another genetic phenomenon. We believe that the congenital absence of teeth has a mendelian dominant inheritance but that penetrance of the gene is reduced to approximately 50 percent. Some extensive family histories are in agreement with dominant inheritance. A number of others have probands whose parents were normal. It is always probable that more than one genotype is responsible for one phenotype. In some family histories, though, the data support the conclusion that an oc¬ casional "normal” person had a dominant gene for the trait. To cite one such case: a family history includes a number of affected members, each having the severest anomaly (both teeth absent). Each affected person had an affected parent, with one exception. One woman with a full complement of permanent teeth had a mother and several close relatives with the trait. The normal woman produced a child lacking both upper lateral incisor teeth. This was the only evidence of skipping a generation in the family group. It is considered to be an instance of failure of a dominant gene to be expressed in the parent. There are other family histories with similar patterns. Table I INDIVIDUAL VARIATION— UPPER LATERAL INCISOR TEETH Type of Anomaly Propositi % Relatives of Propositi Total Cases % Missing both sides 97 45.8 72 169 50.6 Peg-shaped both sides 23 10.8 23 46 13.8 Missing one side Peg-shaped 33 15.6 5 38 11.4 Missing one side only 32 15.1 10 42 12.6 Peg-shaped one side only 16 7.5 9 25 7.5 Supernumerary 11 5.2 3 14 4.2 TOTALS 212 100.0 122 334 100.0 1953, No. 1 March Trait Frequencies in Human Population: 13 PTC TASTE DEFICIENCY Another trait has many factors which make it a good one for compara¬ tive studies of populations. Yet some workers shy away from its use. This is the ability to taste phenyl-thio-carbamide. A genetic basis for the trait has been established. Inability to taste the compound is recessively inherited. Racial groups differ in the proportions of tasters and non-tasters among their members. Anglo-Americans have a relatively low proportion of tasters as compared to other racial groups. Snyder (1932) reported that 70.2% of U.S. whites are tasters. Among American Indians 93.9% are tasters (Levine and Anderson, 1932). In U.S. Negroes the frequency is 91.8% (Lee, 1943). Rife (1948) also reported that cultural groups within a race vary in their relative frequencies of tasters. Difficulties arise, however, because of variations in taste reactions among persons who are tasters. Some taste the substance as soon as it is touched to the tongue. Others require a longer time before they recognize that the chemical is present. A low concentration can be tasted by one person but not by another, although the second may be able to taste a higher concentration. It is not possible, therefore, to use the trait for com¬ parative studies of groups unless similar methods are used to separate tasters from non-tasters. We are now using PTC tests in a comparative study of three racial groups in this area. Up to this time, our data show that the Anglo-Americans have the lowest proportion of tasters, Mexican-Americans the highest, and U.S. Negroes an intermediate frequency. Our completed records on all ex¬ cept the Anglo-Americans are relatively few, but the studies are being con¬ tinued. Family histories collected by Hagy show some of the complications which may arise in deciding who are tasters and non-tasters. Parents and children sometimes differ in their threshold of taste reaction. In one family, a man who could taste the chemical only if a high concentration (0.2%) was used married a woman who could not taste even that high concentra¬ tion. They produced two non-taster and two taster children, one of whom could taste a 0.1% and the other a 0.05% concentration. medical care and custom Health regulations and medical care may play a part in determining the occurrence of traits in the various racial groups. This may be important in sub-populations of one racial group. The traits may, of course, occur so infrequently that they are not too useful for population studies. Epidemics can cause a particular trait to occur with a high frequency at a particular time and thus be responsible for results which can not be repeated. The trait may be similar to hereditary traits found in another population. German measles in a woman during early stages of pregnancy has been reported as a cause of eye, heart, and ear defects in the developing child. This association was first reported from Australia. Several workers (Erickson, Albaugh) have reported similar findings in this country. An area in which lack of knowledge about the disease or where quarantine regu¬ lations are not practiced may have an epidemic of the disease. The result could be a "temporary” high incidence of congenital cataract, corneal capacity, heart lesions and microphthalmus. 14 The Texas Journal of Science 1953, No. 1 March A parasite, Toxoplasma, is reported to be responsible for certain defects in some children who are infected during their fetal history (Adams et al, 1946). These traits include hydrocephalus, microcephalus, microphthalmus and chorioretinitis. In some areas, infection is known to be epidemic in nature. Regions which vary in rate of infection may therefore differ in frequency of defects related to the parasite. COMPARATIVE AGES OF POPULATIONS The age of members of a population may be an important factor in determining the morbidity rate for that population. Cancer of certain sites, such as breast, stomach, and prostate, would be expected to occur with high¬ er frequency in an older population than would be true in a population having a lower average age. Congenital characteristics are found in some instances to be correlated with maternal age. This may be a phenomenon related to a change in the physiology of all older women. It may be due to a particular genotype in which the penetrance or expressivity depends upon the mother’s physiology during her pregnancies. Reports have been made of anomalies which occur more frequently in children produced by older women, and in some cases in those by younger women. As a type case we will consider mongolism. MONGOLISM The physical features characterizing mongolism are easily recognized in all expect the less severe cases. Mongolism has been reported in at least three racial groups. The majority of cases so far reported have occurred in the Caucasian race. This is so probably because more complete studies have been made of this race. In Caucasians, mongolism occurs no less frequently than one per 1000 births. Opinions differ as to how important heredity is in causing mongol¬ ism. Twin-studies support the conclusion that heredity is one factor. Most sibships, though, include no more than one affected child, but this is usu¬ ally the last member. Families having another child following a mongoloid child represent only a small proportion of the sibships having an affected member. Some of these families do have two or more mongoloid children. One condition found to be closely associated with the occurrence of mongolism is increased age of mothers. More than one-half of mothers of mongoloid children are 3 5 years of age or older. In contrast, approximately 15 percent of all births in 1940 were by mothers in that age range. The probability that a woman will produce a mongoloid child rapidly increases with her increase in age (Benda) provided the circumstances present that potentiality. A woman who has produced one mongoloid child faces a risk that a subsequent pregnancy will result in another mongoloid. This chance is 40 times that for a woman in the same older-age group who has not produced a mongoloid child earlier in life (Oliver, 1950). At least two cultural factors may cause two populations to differ for frequency of mongolism. We can assume that both groups of people have any potentiality necessary for the trait to develop. If two groups have similar customs of early marriage and reproduction is rapid, the life expectancy of marriageable women influences the relative rates of mongolism. The popu¬ lation with an early average age of death should have a low rate of mongol¬ ism among the children. Mothers in this group just do not live long enough 1953, No. 1 March Trait Frequencies in Human Populations 15 for many of them to develop the essential environment associated with in¬ creased age. The group with a later average age of death will have a high mongolism frequency if the women continue to reproduce throughout the reproductive age, a factor we assumed. The children born to the older women will face the proper envirnoment for the potentiality to be expressed. Two populations in which social or economic pressures cause women to marry at different age levels may have unlike frequencies of mongoloid children. Again we must assume that both groups have the same potentialities. A woman in a population where custom and opportunity result in early mar¬ riages is more likely to have a large family. Most of her children will be born before she had the physiological changes making a mongoloid possible. Therefore the ratio of mongoloid to non-mongoloid children will be low. A woman in another group where late marriages are the rule will tend to have a smaller family. A high proportion of her children will be produced after the mother is in the critical age level, depending of course upon when she began bearing children. The proportion of mongoloids among all children should be relatively high in this group. This emphasizes the error in count¬ ing the ratio of mongoloids to all sibs. The more accurate measure is to determine the ratio among sibs born after mothers have reached the critical age. If this is done, the two populations may show similar trait frequencies. It becomes necessary to know something about the cultural life of the populations. Comparative ages should be taken into consideration. Obviously it is essential that the investigators know whether conditions of life have any effect upon the trait occurrence. OTHER FACTORS There are a number of other factors which may have an effect on trait frequency and gene frequency. Although it is not possible here to discuss these factors, some mention of them may be made. Any condition which affects the free interchange of genes will be effec¬ tive. This condition may arise because a group of people is isolated geo¬ graphically or culturally from other groups. Selection of mates, or assortive matings, will affect trait frequency. Selection against a trait by action of man himself can be a factor. Mutation can not be ignored. Repeated muta¬ tions may increase the frequency of a form of the gene. There can also be more than two forms of the gene occurring as a result of mutations. SUMMARY 1. Additional data about known hereditary traits prove useful in dif¬ ferentiating people into definite genetic groups. This can best be shown by the use of blood groups. New blood types and sub-divisions of known types have been used to help establish that populations having similar character¬ istics as based upon coarse phenotypes actually are genetically different as determined by the use of finer phenotypes. 2. Some traits are more difficult to use because of varied manifestations which may also result in reduced penetrance. Congenital absence of teeth may actually occur with different frequencies in two populations. The difference will seem greater than it actually is unless workers whose data are compared have given due consideration to all variations of the trait. Diffi¬ culties in technique as well as in variability, as shown by threshold differ¬ ences, may prevent measurement of true frequencies of traits such as PTC taste deficiency. 16 The Texas Journal of Science 1953, No. 1 March 3. Medical care and sanitation practices can be responsible for differences in frequencies for certain traits. Some diseases result in anomalies, many of which mimic hereditary traits. In localities where poorer health regulations are followed, an epidemic may occur and result in an increased frequency for a particular trait. German measles and toxoplasmosis are two diseases which may cause anomalies in children. 4. Custom as well as medical care are two factors affecting the average age of a population and differences in frequencies of traits closely associated with age. One of the most striking effects of age of mothers is mongolism. The trait occurs most often in children borne by older mothers. Differences in life expectancy and therefore in average age of marriageable women may result in unlike rates of mongolism for the populations. If customs lead to differences in age of marriage, the effect may be unlike frequencies of mongoloid children. In the latter case, the difference can well be due to our error in determining the frequency of occurrence of the trait. LITERATURE CITED Adams, F. H., R. Horns, and C. F.KLUND — 1946 — Toxoplasmosis in a large .Minne¬ sota family. Jour. Pediatrics 28= 165-171. Albaugh, C. H. — 1945 — Congenital anomalies following maternal rubella in early weeks of pregnancy. JAAiA 129: 719-723- Benda, C. E. — 1946 — Arlongolism and Cretinism. New York, Greene and Stratton Inc. 316 pp. Brekhus, P. J., C. P. Oliver, and G. Montelius — 1944 — A study of the pattern and combinations of congenitally missing teeth in man. Jour. Dent. Research 23: 117-131. Erickson, C. A. — 1944 — Rubella early in pregnancy causing congenital malforma¬ tions of eyes and heart. Jour. Pediatrics 25: 281. Hagy, G. W. — 1948 — A study of thresholds and individual taste patterns for phenyl- thio-carbamide in the human. Master of Arts Thesis, University of Texas, Austin. Lee, B. F. — 1943 — A genetic analysis of taste deficiency in the American Negro. Ohio Jour. Science 34: 337-342. Levine, P., and A. S. Anderson — 1932 — Observations on taste blindness. Science 75: 497-498. Oliver, C. P. — 1950 — Mongolism: Multiple occurrence in sibships. Eugenical News 35: 35-39. Oliver, C. P., P. J. Brekhus and G. Montelius— 1945-— Study of congenitally missing second premolars and space factors in the arches. Jour. Dent. Research 24: 217-221. Race, R. R. — 1951 — The eight blood group systems and their inheritance. Cold Spring Harbor Symposia on Quantitative Biology 15: 207-220. Rife, D. C. — 1948 — Genetic variability within a student population. Amer. Jour. Physical Anth. N.S. 6: 47-62. Snyder, L. H. — 1932 — The inheritance of taste deficiency in man. Ohio Jour. Science 32: 436-440. FACTORS AFFECTING GENE EXCHANGE BETWEEN POPULATIONS IN THE PEROMYSCUS MANICULATUS GROUP W. FRANK BLAIR University of Texas INTRODUCTION The diflferentiation of geographic sub-populations within a species population and the origin of new, discrete species populations are directly related to gene transfer and survival in natural populations. The biological phenomena of geographic differentiation and speciation are, therefore, im¬ portant phases of the general field of population genetics. We hold to the current, genetic concept of the species as a potentially interbreeding popu¬ lation or series of populations without being any more able than others who have attempted it to define the species so precisely as the classifier of animals might wish. The rate of dispersal of hereditary characters through a species popula¬ tion is a complex quantity that may be affected by environmental factors, by the dynamics of the population itself and by the pattern of distribution of the population. A mutation theoretically might be eliminated at the point of origin if it was sufficiently disadaptive for that environment and if its effects were such that it was immediately subjected to selection. A locally adaptive genotype would be subjected to increased selection pressure as it spread into areas to which it was poorly adaptive, and selection pressure alone could theoretically retard or inhibit the spread of hereditary characters. The tendency for an individual to remain in an area of familiar terrain, once sexual maturity has been reached, tends to inhibit the mixing of here¬ ditary materials between sub-populations. On the other hand, the tendency for maturing young individuals to disperse from the point of birth at the approach of sexual maturity favors gene exchange between sub-populations. The pattern of distribution of the whole species population, whether in numerous semi-isolated colonies or in an areally continuous population (in the sense of Wright, 1943), also affects the rate of gene dispersal and conse¬ quently the amount of local differentiation within the whole population. The deer-mouse (Peromysctis maniculatus) has been more thoroughly studied in respect to the factors that might affect gene exchange in natural populations than probably any other terrestrial vertebrate. No previous attempt has been made to bring together the information from many inde¬ pendent and more or less unrelated studies in an effort to determine the principal mechanisms affecting gene exchange in this species. THE DEER-MOUSE AS MATERIAL FOR STUDYING GENE EXCHANGE The deer-mouse is probably the best rodent in North America in which to examine the factors affecting gene exchange and to attempt to analyze the effects of these factors in a natural population. The population of rodents 1 Read at a symposium on "Population Genetics” at the annual meeting of the Texas Academy of Science, Austin, Texas, December 8, 1951. 17 18 The Texas Journal of Science 1958, No. 1 March currently known as Feromyscus manicnlatus appears to be a comparatively old species as rodent species go. It is probably the most widely distributed native small mammal in North America, It occurs in a wide diversity of environments, and it has undergone a great deal of geographic differentiation. The degree of geographic differentiation in this widely distributed species is indicated by the fact that some 28 continental, geographic races and some 3 6 insular races are currently recognized by taxonomists. Four other species have apparently split off from the maniciilatus population, and several aspects of the relationships between one of these species and the parental manlculatus population have been investigated by several workers. The present, complex distributional pattern of the manlculatus popu¬ lation and its putative offspring species populations apparently traces to Pleistocene distribution patterns and to major post-Pleistocene shifts in the distribution of segments of these populations. Long-tailed, forest-inhabiting manlculatus, which today occupy a roughly U-shaped distribution from the Rocky Mountains and coast forests of the west, eastward across northern Canada, and southward in the Alleghenies, possibly ranged across the plains of central North America as late as the Wisconsin glacial stage. With increasing post-Pleistocene aridity in the plains, forcing withdrawal north¬ ward of the forests, the present distribution of the long-tailed forms could have been achieved. The short-tailed manlctilatus presently occupying the central grasslands could have evolved In situ, but is seems more likely that they spread into this area from a Pleistocene refuge in Mexico or the south¬ western United States. The effects of this past distributional history have, as we will see, an important bearing on gene exchange in the manlculatus population. In addition, the population known as Feromyscus pollonotus possibly was exchanging genes with the grasslands population of manlculatus as late as the Pleistocene (Blair, 19 5 0), FACTORS AFFECTING GENE EXCHANGE IN THE FeVOmySCUS Manlculatus population POPULATION DYNAMICS — Individuals of this species establish a home range at about the onset of sexual maturity, and they tend to remain in this area of familiar terrain through the remainder of their life. Blair (1943a) reported an average home range of 4.66 ± .3 3 acres for males and 4.10 ± .39 acres for females in open mesquite in the Tularosa Basin, New Mexico. Howard (1949) reported that home ranges covered five to six acres in bluegrass fields in southern Michigan. In forest environments, these mice apparently range less widely than in grasslands. Blair (1942) reported an average range of 2.31 db .27 acres for males and 1.39 ± .16 acres for females in beech-maple forest in northern Michigan. Murie and Murie (1931) reported that the diameter of the home range was about 100 yards in Wyoming forests. Even smaller estimates of only .24 acre for males and ,21 acres for females were given by Storer, Evans, and Palmer (1944) for this species in California forests, but their estimates are open to question because of technique. The available evidence indicates that the reproductive phase of the life history is usually spent within an area of probably four to six acres in the case of grassland-inhabiting manlculatus and in perhaps one-half this area in the case of forest-inhabiting populations. The fact that breeding pairs are formed (Howard, 1949) minimizes the chance of gene dispersal through mating of individuals in adjacent, overlapping home ranges. In 1953, No, 1 March Factors Affecting Gene Exchange 19 Peromysctis polionoftts, which also forms more or less permanent pairs, the home range of one mouse of a pair is largely superimposed on that of the other (Blair, 1951). Gene distribution in the population is effected chiefly through the dis¬ persal of young individuals as they aproach sexual maturity. Howard (1949) believes that the dispersal movement is stimulated by hormonal activity associated with the onset of sexual maturity. Blair (1940a, 1951) believes that population pressures may affect the distance of dispersal, Le,, a dis¬ persing individual may travel until it reaches a suitable enviror.ment in which competition is low, perhaps through the recent loss of one or more established residents. The information about dispersal is far from adequate, but seme facts are available. Maximum dispersal distances recorded for this species in blue- grass fields are 3960 feet (Blair, 1940a) and 3300 feet (Howard, 1949). Average distances of dispersal of 13 34 feet for males and 45 3 feet for females in this habitat were reported by Blair (1940a). Howard (1949) found that only 3 1 per cent of young males and 1 5 per cent of young females dis¬ persed more than 500 feet before establishing home ranges and reproducing. The maximum distance of dispersal reported from open mesquite desert is 2300 feet (Blair, 1943a). This evidence suggests a fairly low rate of dis¬ persal in Peromyscus maniculatus. Taking Blair’s (1940a) estimate of average dispersal distance and Howard’s (1949) estimate that as many as four gen¬ erations may be produced per year, we can estimate crudely the maximum distance a mutation might be dispersed in a year. In the simplest case (linear distribution and linear dispersal), and averaging the rather different dis¬ persal distances for the two sexes, a mutation could theoretically disperse at an average rate of about two-thirds of a mile per year. This is an idealized case, of course, which would be rarely approximated in nature, for it does not consider such important factors as ecological barriers and the selective elimination of disadaptive types. Consideration of these factors involves an analysis of the patterns of distribution of the species population. PATTERN OF DISTRIBUTION — The geographic range of Peromyscus maniculatus in the United States may be divided into several major regions on the basis of ecologic preference and local pattern of distribution. This species ranges far northward in the Canadian forests and southward into Mexico, but these regions have been mostly omitted from the present dis¬ cussion because of the paucity of work outside of the United States. Present information bearing on the pattern of distribution and its effects on geo¬ graphic differentiation in the major regions is summarized below. Northeastern Forests. The forest-inhabiting deer-mice of eastern Canada extend southward in a peninsular-type distribution along the Appalachian chain of mountains (Fig. 1). These are long-tailed, dark-colored, semi- arboreal mice that appear to be restricted to forest habitats. In eastern Tennessee, Kellogg (1939) reported them from forest habitats between 2700 feet in hemlock forest and 5700 feet elevation in birch and spruce, although the mice were recorded from both coniferous and deciduous forests in the mountains. In Pennsylvania, Rhoads (1903) listed this species as "confined to the denser hemlock, tamarack and white pine forests” and "balsam forest belts of the higher southern Alleghenies.” In New York, Harper (1929) stated that the deer-mouse was the most abundant mammal of the Adiron- dacks, where it ranged through virgin forests and second-growth thickets 20 The Texas Journal of Science 1953, No. 1 March 1953, No, 1 March Factors Affecting Gene Exchange 21 up to above timberline. In southwestern Virginia, Hooper and Cady (1941) reported deer-mice from heavy stands of mature hardwood and mixed pines at an elevation of 3 600 feet. The peninsular population of the eastern moun¬ tains apparently shows what Wright (1943) calls areal continuity of dis¬ tribution, but it seems probable that there is semi-isolation of sub-populations on isolated mountains. The information is not available to show how much restriction on gene flow is imposed by the avoidance of some habitat types in the area of more or less continuous distribution. There is more information for northern Michigan, Dice and Sherman (1922) found deer-mice to be most abundant in dry hardwood forest and recorded them from 10 other habitats. They did not report the species from 10 other habitats and 10 additional minor, shore habitats investigated in Gogebic and Ontonagon counties. In Charlevoix County, Michigan, Dice (1925) reported forest-type deer-mice as most common in hardwood forest and present in three other vegetation types. He did not report them from 20 other habitat types studied. He listed the short-tailed grassland race from sand and gravel beaches and from dune sands. Manville (1949) studied population densities in eight forest types in Marquette County, Michigan, and reported the occur¬ rence of deer-mice in all forest types studied, although they were rare in jack-pine and black spruce. The evidence from Michigan points to a mosaic distribution, with the exchange of individuals between populations in suitable forest types more or less restricted by the interspersion of unfavorable habi¬ tats. Selection would presumably be for a type adapted to forest life. The most interesting point about the eastern, forest deer-mice is that there appears to be no interbreeding with the short-tailed, grassland- inhabiting deer-mice to the west of them. Cleared Deciduous Forest. The short-tailed, grassland-inhabiting popu¬ lation of maniculatus has apparently spread eastward and northward with the clearing of the forests in historic times so that it now approaches or overlaps the range of the eastern and northeastern forest populations. The story of this eastward and northward movement is fairly well documented. Osgood (1909) recorded the short-tailed bairdii from as far east as London, Ohio, from Sand Point on Lake Huron in Michigan, and from extreme southwestern Ontario. Enders ( 1930) reported this form as far east as Wayne County, Ohio, where specimens were taken in a young orchard, along roads and in weeds. Mitchell (1934) reported breeding adults from within the city of Meadville in northwestern Pennsylvania. Moulthrop ( 1938) FIG. 1. Geographic clistribudon of Peromyscus maniculatus and Peromyscus polionotus in the United States, showing variation in pelage color, body length, and tail length as indicated by work of L. R. Dice and his associates. Subdivisions of range of P. maniculatus on basis of pattern of distribution: (A) northeastern forests, (B) cleared deciduous forest, (C) central prairies and plains, (C’) Nebraska sand hills, (C’) Black Hills, (D) Rocky Mountains, (E) Columbia Basin, (F) Pacific Coast forest, (G) basin and range. Each symbol represents a sample. Shading of circle indicates mean value for reflected red as measured with Ives tint photometer. Tint photometer reading in¬ creases with increase in paleness of pelage color. Solid circle, reading of 3. 1-7.0; cross-hatched, 7.1-11.0; parallel-ruled, 11.1-15.0; open circle, 15.1-22.3. Unshaded circles of broken lines represent samples from, author’s data for which no tint photo¬ meter readings are available. The arm to the reader’s left shows body length scaled from 52.5 mm. as zero; the right arm shows tail length similarly scaled. 22 The Texas Journal of Science 1953, No. 1 March reported this form from open fields in Genesee County, New York. Hamil¬ ton (1950) reported this form from fields in the vicinity of Ithaca, New York, where it now reaches the range of the forest-inhabiting populations. Kellogg (1939) reported the prairie form from northern Tennessee, where specimens were taken, "alongside logs in a drained cypress swamp.” There also appears to have been a northward spread of the prairie form in Michigan following cutting of the forests in historic times. Dice (1920) reported prairie deer-mice from cleared uplands and from wheat fields in southwestern Michigan, but he did not record this species from eight other habitats in the same area. Dice ( 1925 ) reported the prairie form from beaches and dune sands in Charlevoix County, where the range of this form now reaches the range of the forest population. Dice (1932) stated that the prairie deer- mouse exists in large numbers on the wide sandy beaches of the Great Lakes in Michigan. In southern Michigan, the prairie deer-mouse occurs most commonly in cleared land that has grown up in bluegrass and other herbs. Near Detroit, Leraas ( 193 8a) found this form most common in meadows of bluegrass, timothy and quackgrass and recorded it from five other habi¬ tats on cleared or open ground. He did not find it in forests. The northward extension of the prairie deer-mouse in Michigan has been discussed by Hooper (1942) who also reported that this form has moved northward along the west side of Lake Michigan to Menominee County, Michigan, where it now has reached the range of the forest population. Hooper has found no evidence of interbreeding of the grassland and forest populations of maniculattis in Michigan, a fact which he attributes to ecological isolation of the two. In this respect, Blair (1940a) found that the prairie deer-mice of bluegrass fields were generally absent from a strip about 50 to 100 feet wide bordering adjacent oak-hickory woods. Another species, Peromysctis leucopns, occupied the forest and ranged out into and beyond this strip into the grasslands, and the prairie mice may have been kept out of the woodland border by competition from the leucopns. If not, the avoidance of the forest border by the prairie deer-mice might account in part for the effectiveness of the ecological isolation of the prairie and forest forms. It should be kept in mind that the several contacts between the prairie and forest forms in Michigan and New York are apparently of rather recent origin, and there is no cer¬ tainty that these populations will not interbreed as the prairie form spreads into the range of the forest form. There is no evidence at present, however, that these populations are exchanging genes. The distribution of the prairie deer-mouse in the regions that it has invaded in recent years is a very mosaic one, because forests are ecological barriers for this form. Farm woodlots, forests left standing on rough ground and second-growth thickets tend to partially isolate the deer-mouse popula¬ tions of fallow or cultivated fields. Within the limitations of this distribution pattern, the populations of this newly invaded area apparently interbreed with their parent populations to the west but do not interbreed with the forest populations to the north and east and probably have not done so since the Pleistocene. Central Prairies and Plains. The short-tailed, grassland-inhabiting deer- mice of central North America are probably more evenly and continuously distributed than those in any other major part of the species range. This population, adapted as it is to life in grasslands, finds agricultural lands no barrier, and it may even reach greater population densities in cultivated or disturbed areas than in native grassland. Numerous observations indicate 1953, No. 1 March Factors Affecting Gene Exchange 23 the preference for grasslands or farmlands and the avoidance of forests by this form. In Iowa, Stoner (1918) reported the prairie deer-mouse from dry cultivated fields and prairies and stated that it does occur to some extent in small, sparsely wooded areas. In southwestern Missouri, Jackson (1907) wrote that this form favors open brushland, but stated that he took one in heavy timber high up on a hill. In Kansas, Dice (1923a) took this mouse in prairie, rocky ground, and sumac scrub, and he recorded two from oak forest in winter. In northeastern Oklahoma, Blair ( 1938) recorded it from tallgrass prairie, grama-beardgrass prairie and from habitats in which sumac or scrubby plums were mixed with grasses, but he failed to find it in forest habitats. On the Salt Plains of northwestern Oklahoma, Jackson and Warfel ( 1933 ) reported this mouse from almost any habitat of the region, including rocky ledges, barren tops of hills and islands bordering the plain. In south¬ western Oklahoma, I took it in grasslands bordering the Red River, and in the Texas Panhandle I took it on sand dunes with tall grasses and sand sage and on the grassy floodplain of a tributary of the Canadian River. In south¬ eastern Oklahoma, McCarley ( 1950) reported this mouse as common in tail-grass prairies but found it in no other habitat. This form extends south¬ ward in a peninsular distribution in the tail-grass prairies of eastern Texas, but it becomes local and spotty in distribution as it approaches the southern limits of its range. On the coastal plain east of Austin, this mouse is largely limited to local populations on "blackland” clays with native vegetation or in cultivated crops. At Alice, Bailey ( 1905 ) reported one from open prairie, and at Washburn in the Panhandle he reported this mouse from short-grass plains and from prairie at the edge of fields. This species is apparently absent, or very rare, on the Edwards Plateau and on the plains between it and the Red River in Texas. In South Dakota, Dice (1942a) reported the prairie form from areas of thin vegetation in the Badlands. The deer-mouse becomes more versatile in its ecological tolerance in the northwestern parts of the plains than it is in the eastern prairies. In North Dakota, Dice (1940) collected this form in natural and pastured prairies, in grassy fields, in weedy fields, and along railroads bordered by grass or wheat. In eastern North Dakota, Bailey (1926) reported this mouse from tail-grass prairies, brushy, weedy bottoms in woods, half-dried tule marshes, weed rows, and grain fields. In western North Dakota he (op. cit.) reported it as about equally abundant in prairies, badlands buttes, marshes, and wooded bottoms. In southern Manitoba, Sanderson ( 1950) found deer- mice common in fallow fields and reported a few from the edge of a prairie grove of eighteen-year-old trees. In Montana, Dice (1944a) took this form in open fields and in northeastern Utah he took it in a short, steep canyon where grass and sagebrush alternated with juniper and other trees. Although there appears to be less restriction on the exchange of indi¬ viduals within the prairies and plains than in other regions, some barriers to dispersal do exist. Floodplain forests that extend far out into the plains along the streams are at least partial barriers, of unknown effectiveness, between the populations of adjacent uplands. In the more arid parts of the plains, the local distribution seems to be correlated with soil type, and populations on sandy, friable soils may be partially isolated by intervening, non-friable soils. Morphologic evidence that the central-grasslands population inter¬ breeds with the manicnlatus population of the Rocky Mountains along the eastern front of the Rockies in Colorado and northern New Mexico and in 24 The Texas Journal of Science 1953, No. 1 March southwestern Canada has been presented by Osgood (1909). There is similar evidence of interbreeding between the plains and the basin-and-range popu¬ lations in northeastern Utah (Osgood, op. cit.). In Glacier Park, Montana, the grassland and forest populations meet but apparently fail to exchange genes because of their different ecologic preferences (Murie, 1933 ). The prairie and plains mice tend to be small, short-tailed and dark- colored, but there is an increase in length of the tail and in paleness of the pelage color toward the west. The apparently greater uniformity in mor¬ phologic characters in the eastern part of the grasslands than in the west may possibly be due in part to the greater continuity of distribution and in part to the greater uniformity of the environments occupied. In the eastern grasslands, the deer-mice are almost entirely restricted to fairly level grasslands, with either native or introduced grasses and herbs, and the soils in this region of comparatively high rainfall are predominantly dark in color. Parallel selection in comparatively similar environments might ac¬ count, in large part, for the similarity of the eastern grasslands deer-mice. Two regions in the western part of the grasslands have deer-mouse populations that depart strikingly from the general characters of the grass¬ lands populations. One of these is the Nebraska sand hills, and the other is the Black Hills. On the pale sands of the Nebraska sand hills. Dice (1941) found the deer-mice to be predominantly paler in color than the mice on the darker soils completely surrounding this area of pale-colored soil. Many of the sand-hills mice are a rich, clear yellow-orange in color, and Clark ( 1938) has shown that this color is dominant over the darker, duller color of prairie deer-mice to the east of the sand hills. Dice (1941) noted that even in the interior of the sand hills the population was quite variable, with both color types represented. Blair (1947a) examined 166 held-caught mice from the sand hills and recorded 124 of them as of the dominant color and 42 as of the recessive. Dice (1941) attributed the vari¬ ability of the sand-hills mice to interbreeding with the darker-colored popu¬ lations which surround the sand hills on every side, and he also concluded that intergrading populations surround the sand hills for ten or more miles on every side. The existence of the predominantly pale-colored, but variable, population on the sand hills is taken to indicate an intensity of selection there sufficient to retard but not prevent the infiltration of genes for dark pelage color from the populations on the surrounding, dark-colored prairie soils. Dice {op. cif.) reported a similar, pale-colored population on a smaller, isolated sand area south of the Platte River. In the Black Hills of western South Dakota, Dice (1939a) found deer-mice most abundant in forests and scarce in grasslands to the east and south of these hills. He found the greatest abundance of mice in dense and medium-dense stands of western yellow pine and also recorded this species from mixed aspen and yellow pine, sparse yellow pine and young stands of yellow pine. The deer-mice in the heavily forested upper part of the Black Hills, where the soils are consequently dark, have pelage darker than the regional average (see Dice, 1942a). Rocky Mountains. The deer-mouse is principally a forest inhabitant in the Rocky Mountains, where the tail tends to be moderately long and the color moderately dark. In Colorado, Cary (1911) reported the deer-mouse to be almost omnipresent in the mountains, where it lives indiscriminately in heavy forests, in mountain bogs and among sagebrush in mountain parks. In the same state. Dice ( 193 3a) collected deer-mice in rocky talus of the 1953, No. 1 March Factors Affecting Gene Exchange 25 pinon-cedar belt and in brushy thickets. In northeastern New Mexico, Hill (1942) found deer-mice common in mixed yellow pine and scrub oak. At Flathead Lake, in Montana, Dice ( 1923b) found deer-mice most common in larch-Douglas fir and spruce-fir habitats, but also recorded it from four other forest types and from bunch-grass, mountain meadow and beach habitats. In the same state and in Idaho, Dice (1944a) collected deer-mice in heavy cedar forest, at 95 00 feet elevation near timberline, in a wide valley with mostly grass, and on the cinder slopes of a volcanic cone. Columbia Basin and Edge of Pacific Coast Forest. In the Columbia Basin of Washington and Oregon, the deer-mouse occupies a wide variety of environments, apparently because this is a place where grassland and forest populations meet, interdigitate, and apparently interbreed. In south¬ eastern Washington, Dice (1914) recorded this species from 14 habitats, ranging from bunch-grass hills to alpine-fir and Douglas-spruce forests, and reported that it was taken in every land habitat studied in the Blue Mountains. Dice (1939b) collected stocks in nine habitats, ranging from open bunch grass, buckbrush, or second-growth brush to willows, lowland fir, or yellow pine. Fox (1948) found similar evidence of wide ecologic tolerance in the Columbia Basin, for he collected deer-mice in grass and sagebrush, oat and alfalfa fields, sagebrush, and spruce, fir, larch, lodgepole pine-fir, spruce and hemlock forests. This is an area of great local variability in dimensions and in pelage color, both apparently correlated with environmental variations. Dice ( 1939b) has pointed out the tendency for the palest deer-mice to occur in the sagebrush climatic belt and in the more arid parts of the bunch-grass belt, while the darkest mice occur in less arid parts of the bunch-grass belt and in the relatively humid montane climatic belt, where surface soils tend to be dark in color. He believes that the Snake River has long existed as a barrier to the movement of deer-mice and attributes similar pelage colors of mice living in corresponding life belts on opposite sides of the river to parallel evolution. Dice (1949) regards the Columbia River as an important physical barrier to the movements of deer-mice and believes that the charac¬ ters of the habitat are more important in controlling the characters of the mice than are the physical barriers to their distribution. Fox (1948), work¬ ing in the same region, found that dark-colored, long-tailed, long-eared forms were almost always found in thick forest areas, while light-colored, short-tailed, short-eared forms were found in open bunch grass or sagebrush. He believed that exceptions to this generalization might be explained on the basis of gene flow in excess of selection pressure. This appears to be a region of great genetic variability, which persists because the deer-mouse occupies widely diversified environments and is being selected for adaptive genotypes in each different habitat. Selection would appear to be probably the major factor affecting gene distribution in this area. The populations of this region apparently interchange genes with the populations that surround them on all sides, although there is some indica¬ tion that there may be restricted exchange with the very-long-tailed popula¬ tions of the dense coast forests. Osgood (1909) reported that the form typical of the coast forests occurred in some places with the form typical of the inland forests without either form losing its respective characters, but in other places he found extremes of both forms along with intermedi¬ ates, and in others he found intermediates only. Fox (1948) believes that these forms interbreed, but not freely, for he found the parent types more 26 The Texas Journal of Science 1953, No. 1 March common than intermediates in the region of apparent interbreeding. Dice (1949) took both forms together in the same local habitats and where there seemed to be no ecological barrier between them. McCabe and Cowan ( 1945) reported the two forms from the same region in southwestern British Columbia. Pacific Coast Forests. The deer-mouse is a forest inhabitant in the dense forests of the Pacific coast in British Columbia, Washington, Oregon, and northern California. In coastal Oregon, Bailey (1936) reported that the deer-mouse is mainly an inhabitant of dense forest or chaparral. In the Columbia Valley of western Oregon and Washington, Fox (1948) recorded this species from eleven forest and second-growth-forest habitats, from brushy or lightly wooded pasture and from fields of heavy grass, sedge and skunk cabbage. Dice (1949) collected deer-mice in the Puget Sound region of Washington in coastal forest, in second-growth Douglas fir and in a burned area. The question of gene exchange between these long-tailed mice and the shorter-tailed mice to the east has already been discussed. Basin and Range Region. Over a vast area in the West, corresponding roughly to the Basin and Range physiographic province, the deer-mouse occupies grassland or brush habitats in the desert basins and forest habitats on the mountain slopes. In southern Nevada, Burt (1934) reported that the deer-mouse was taken in almost every type of habitat available from the low desert to above timberline, but that it was most numerous above 6 500 feet where Mohave yucca ceases and junipers and pifions begin. In northeastern Utah, Leraas ( 1938b) collected this species in sagebrush at 6000 feet, in a canyon forest of juniper, pine, fir, poplar, willow and birch at the same elevation, and in an open yellow-pine forest with a sparse under¬ growth of sagebrush at 8000 feet. In eastern Utah, Kelson (1951) reported that deer-mice are found in almost all types of environments except aquatic ones from about 3 5 00 to 12,000 feet in elevation. In southwestern Utah, Hardy (1945) recorded this species from Tamarix and arrowweed habitats, but did not record it from eight other desert habitats investigated. In Oregon, Bailey (1936) reported that the deer-mouse occurs in meadows, grasslands, sagebrush, chaparral, in open coniferous and deciduous forests, and on rocks, cliffs and earth banks. In northwestern Colorado, Cary (1911) reported that this species was very common on sagebrush plains and reported it also from cottonwoods and from rocky and pinon country. In the San Francisco Bay area of California, Hooper (1944) reported that deer-mice occurred on ledges of rock, in grass, chaparral or forest but avoided wet areas or areas subject to frequent inundation. McCabe and Blanchard (1950), working in the same area, reported that deer-mice had a linear distribution along the "edge” of the chaparral. In the Sierra Nevada of California, Storer, Evans, and Palmer (1944) found deer-mice in cut¬ over forest at 4500 feet and in pine, cedar, white fir, juniper, black-oak forest at 622 5 feet. In the Grapevine Mountains east of Death Valley, Miller (1946) recorded deer-mice from pinon forest. In the Colorado River Valley of California and Arizona, Grinnell (1914) found deer-mice restricted to the bottomlands of the river and failed to take them on the nearby desert. In the Providence Mountains of California, Johnson, Bryant, and Miller (1948) found deer-mice absent from the creosote belt, abundant in the yucca and sagebrush belts, rare in the pinon belt, and absent in the fir belt. Mearns (1907), working along the Mexican boundary, reported deer-mice in great numbers in pine, aspen and Douglas spruce forests of mountains 1953, No. 1 March Factors Affecting Gene Exchange 27 in Arizona. He reported this species from "aquatic” vegetation beside the San Bernardino River, from meadows and bottoms in the lower portions of the Gila and Colorado Rivers, and from canes, hemp, and coarse grass on the vast savannas of the Colorado River about the head of the Gulf of California. He stated that no mice of this species were met with in the dry region lying between the Santa Cruz Valley and the Gila River at Adonde, Arizona. In Arizona, Dice ( 1938) collected deer-mice in yellow pine, mixed juniper and yellow pine, open oaks, SeneciOy oaks and scrubs along a sandy wash, mesquite, cottonwood, rabbit brush, on lava and cinders, and in cultivated fields. Elevations ranged from 4040 to 8 500 feet. Bailey (1931) reported that in the mountains in New Mexico deer-mice reach their greatest abun¬ dance in open yellow pine but that they are often taken in dense spruce and fir, while in the basins they are generally found in mellow spots of open valley bottoms. In Valencia County, New Mexico, Hooper (1941) found deer-mice in fairly open forests of yellow pine, aspen, and oak brush on the mountains and among sage on sandy desert flats. In the Tularosa Basin, New Mexico, Dice ( 1930) found deer-mice to be abundant in mesquite, and he recorded the species from creosote, atriplex, alkali-flat, and sumac-yucca habitats. In the Sacramento Mountains to the east of the basin, he reported deer-mice most abundant in Douglas fir, but recorded them also from spruce-fir, yellow pine, oak-chaparral, pinon-cedar, and rocky arroyo habitats. He did not find them in sotol-ocotillo or oak- poplar habitats. In this same general region. Dice (1944b) collected deer- mice between 6200 and 8900 feet elevations in short grass, oak brush, pinon-juniper-yellow pine, yellow pine, Douglas fir, and meadows which he thought to be old farm clearings. Dice (193 0, 1942b) has pointed out that on the western slopes of the Sacramento Mountains deer-mice are largely absent from the lower slopes of the mountains, with the result that there is little or no interbreeding between the populations of the dense, montane forests and the populations of the desert basin. In the Tularosa Basin, Blair (1943b) found that the comparatively large populations of mesquite areas and grassy washes were isolated from one another by ex¬ tensive areas of creosote bush or atriplex, in which deer-mice were absent or very rare. In Trans-Pecos Texas, the deer-mouse is very discontinuously distri¬ buted. The yellow pine forests of the higher mountains, such as the Davis and Chisos ranges, are without populations of deer-mice, and only grassland populations occur in this area. Bailey (1905) stated that deer-mice in this region inhabit smooth spots in the bottoms of open valleys. In the Davis Mountains region, Blair (1940b) found populations of deer-mice in short- grass, short-grass-yucca, and short-grass-mesquite habitats but reported these mice absent from all forest belts of the mountains. In the Chisos Moun¬ tains region, Borell and Bryant (1942) also found the mice absent from mountains and encountered them only on the plains in weeds and brush near cultivated fields, in cane and Baccharh on the Rio Grande, in tules at the edge of a small pond, and in grass and weeds. In the Sierra Vieja region, Blair and Miller (1949) found deer-mice only in a black brush-creosote bush habitat of the plains life belt. They were unable to find this species in seven other habitats of the plains belt or in the mountains. Gene exchange and local differentiation in the Basin and Range Pro¬ vince are principally affected by differential selection in montane forests and in desert habitats, and by ecological isolation of populations in this 28 The Texas Journal of Science 1953, No. 1 March region in which many habitats are beyond the ecological tolerance of the species. Populations of the montane forests are generally darker in color and tend to have slightly longer tails than the populations of the desert basins. Gene exchange between these montane-forest populations and the desert- basin populations may be locally restricted or practically non-existent due to ecologic barriers (see Dice, 1930, 1942b) or there may be in other areas continuous distribution from the desert belt to above timberline (see Burt, 1934). Populations in the deserts are much isolated from one another, be¬ cause this species apparently has been unable to occupy the more arid habitats. A recessive mutation to gray pelage color is widely distributed in the desert populations. Osgood (1909) first called attention to the dichroma¬ tism of the desert populations. Dice ( 193 3b) showed that gray pelage acted as a mendelian allele of bluff pelage, and this was confirmed by Blair (1947b) who also called attention to the presence of many modifiers of both buff and gray. Blair (1947c) has shown that there is adaptive differentiation in the frequency of these color genes in the Tularosa Basin under various con¬ ditions of ecological isolation and apparent selection. It is of interest here that the gray mutant apparently occurs rarely in other populations than those of the deserts. By breeding test and by the examination of nearly 2 500 specimens from 172 localities in the range of the species, Blair (1947a) found what appeared to be recessive grays in a population from Troy, Idaho, in the northern Rockies, from a forest population of Isle Royale in Lake Superior, and from a forest population in the Southern Appalachians in Virginia. It is unknown, of course, whether the gray mutation occurred independently in these distant populations or whether it was dispersed there from the western desert populations. Blair (op. r/7.) also found grays in the montane populations of the Sacramento Mountains, which suggests that there may be more interbreeding between the desert populations of the Tularosa Basin and those of the montane forests in the Sacramento Moun¬ tains than was thought by Dice (1930). DISCUSSION The evidence as to details of gene transfer in Peromysms luaniculatiis is far from complete, but it is sufficient to give a broad picture of gene exchange, and its controls, in this widely distributed species. The general tendency for genetic variations to be spread through the entire population through the dispersal of young individuals before they reproduce is retarded by ecological barriers and by selective elimination as the animals disperse into different environments. The failure of populations in adjacent, dissimilar environments to interbreed may have a complex past history of geographic separation and subsequent spread of range. The degree of exploitation of available environments has a direct bear¬ ing on gene transfer and on the number of adaptive types that will be selected for. The exploitation of local habitats by Peroinyscus manicrdaHi$ varies tremendously from place to place, as we have seen from the evidence presented earlier. The reasons for this variation may possibly be traceable to interspecific competition in some cases, or possibly to the genetic potential of the respective populations in others. In a population, such as that of the prairie deer-mice, where the species is essentially limited to a widely and rather continuously distributed and fairly uniform habitat, selection should be acting to maintain an essentially similar genotype throughout the range 1953, No, 1 March Factors Affecting Gene Exchange 29 of the population. In this particular case, restrictions on gene exchange within the population are imposed principally by distance and by such eco¬ logical barriers as rivers and flood-plain forests. Even where there is comparatively continuous distribution, a change in a major feature of the environment (as in soil color in the Nebraska sand hills) may result in selection for a very different genotype than the regional average. This is one of the rare cases in mammals where adaptation is achieved largely through the action of a single gene mutation with major effects on the phenotype. In this case, selection against the recessive, dark pigmentation of the deer-mice that surround the area retards but does not prevent dispersal into this area. The high genetic variability in color of the sand-hills mice (see Dice, 1941) presumably is an indication of gene influx from the surrounding, dark-colored populations. The dominant color gene of the sand-hills mice, which produces a brightly buff phenotype, is ap¬ parently selected against on the comparatively dark, surrounding soils, which hinders its spread in those populations. Where the species is highly euryceous, occupying most available habitats in a region of greatly contrasting environments (as in the Columbia Basin and border of the Pacific coast forest) great genetic variability is main¬ tained, because selection is favoring various locally adaptive types, and because the numerous locally adapted populations are presumably inter¬ breeding with one another. In such a case, the characters of any given popu¬ lation are evidently the result of selection by the local environment and of the immigration of, and interbreeding with, individuals from other popu¬ lations of which the characters are being influenced by selection in other, different environments. In the Basin and Range Province, the situation regarding pattern of distribution and potential gene exchange is rather different from that in any other part of the range of the deer-mouse. In this case, there are num¬ erous and extensive habitats that the species apparently has been unable to invade. The species has adapted, however, to life in the forests of the higher mountains and to life in the least arid habitats of the desert basins. Selec¬ tion in this region, then, is favoring two major ecological types of deer-mice. One is a terrestrial, comparatively shorter-tailed, paler-colored desert form. The other is a semi-arboreal, comparatively longer-tailed, darker-colored forest form. Wide expanses of unfavorable environment in the desert may impose severe restrictions on gene exchange between the local, desert popu¬ lations. Populations in the forested belts of isolated mountains or mountain ranges may not interbreed with the populations of other forests on other mountains, but they may interbreed with the differently adapted populations of adjacent basins. Kelson (1951) has reported intergradation (indicating interbreeding) between montane and desert populations at several localities in eastern Utah. In local instances, there may be little or no gene exchange between the forest and adjacent desert populations (see Dice, 1930, 1942b). This is a pattern of distribution under which selection and ecological isola¬ tion are probably the major determiners of the characters of local populations. Even though there are numerous restrictions on gene dispersal through the Peromyscns maniculatus populations, the aggregate of these populations still conforms to our concept of a species. Although some geographically contiguous populations fail to interbreed directly, all parts of the range of this widely distributed mammal are connected, often circuitously, by inter- 30 The Texas Journal of Science 1953, No. 1 March breeding populations, A mutation that occurred in any part of the range could theoretically be dispersed in time to any other part of the range. The group of populations known as Peromyscus poUonotus is partially separated from the manlculatm populations (Fig. 1.). Geographical isolation has apparently prevented gene exchange between these two groups of popu¬ lations since some time in the Pleistocene (see Blair, 1950). In this case, the elimination of gene exchange over a long period has resulted in greater differentiation than that known between any of the sub-populations of maniculatus. Mating preference would serve to prevent gene exchange if the maniculatus and polionotus ever became sympatric (Blair and Howard, 1944). Partial hybrid sterility would also act as a deterrent on gene ex¬ change (see Watson, 1942; author’s unpublished data). There has been both morphological and physiological differentiation of these geographically isolated groups of populations. Serological differences between maniculatus and polionotus have been reported by Cotterman (1944). The greatest mor¬ phological differentiation involves the occurrence in polionotus but not in maniculatus of an important complex of pattern genes (Summer, 1926; Blair, 1944). SUMMARY The deer-mouse {Peromyscus maniculatus) is used for a discussion of gene exchange between intraspecific populations, because more is known of its population dynamics and geographic variation than is known for any other species of small mammal. The home-range habit and the habit of forming permanent mating pairs tend to restrict gene dispersal. The distance of dispersal of maturing young mice indicates a basic dispersal rate under idealized conditions of roughly two-thirds of a mile per year. The pattern of distribution, ecological barriers, adverse selection, and the effects of past discontinuities in distribution all may affect gene exchange between local sub-populations. The patterns of distribution in seven geographic regions within the range of the species and their possible effects on gene exchange are discussed. A wide range of geographic variation in habitat preference ap¬ parently has important effects on gene dispersal in the whole species popula¬ tion. Little or no direct gene exchange may be taking place between adja¬ cent sub-populations, but all parts of the range are connected, often cir¬ cuitously, by interbreeding populations. The differentiation of Peromyscus polionotus, which apparently has not interbred with any maniculattis population since some time in the Pleistocene, is discussed. LITERATURE CITED Bailey, Vernon — 1905 — Biological survey of Texas. North Amer. Fauna, 25: 1-222. - 1926 — A biological survey of North Dakota. North Amer. Fauna, 49: 1-226. - 1931 — Mammals of New Mexico. North Amer. Fauna, 53: 1-412. - 1936 — The mammals and life zones of Oregon. North Amer. Fauna, 55: 1-416. Blair, W. Frank — 1938 — Ecological relationships of the mammals of the Bird Creek region, northeastern Oklahoma. Amer. Mid. Nat. 20: 473-526. - 1940a — A study of prairie deer-mouse populations in southern Michigan. Amer. Mid. 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Kelson, Keith R.^ — 1951— Speciation in rodents of the Colorado River drainage. Univ. Utah Biol. Ser., 11: 1-125. Leraas, H. J. — 1938a- — Ecological distribution of the mammals in the Cranbrook area. Cranhrook Inst. Sci. Bull., 13: 1-20. - - 1938b — Variation in Peromyscus maniculatus osgoodi from the Uinta Moun¬ tains, Utah. Contrib. Lab. Vert. Genetics, Univ. Mich., 6: 1-13. McCabe, T. T., and Barbara D. Blanchard — 1950 — -Three species of Peromyscus. Rood Associates, Santa Barbara, Calif.: v + 136 pp. McCabe, T. T., and 1. M. Cowan — 1945 — Peromyscus maniculatus macrorhinus and the problem of insularity. Trans. Royal Canadian Inst., 1945: 117-215. McCarley, W. H. — 1950— The ecological relationships of the mammals of Bryan County, Oklahoma. Unpub. M. A. Thesis, Univ. Texas. Manville, R. H. — 1949 — A study of small mammal populations in northern Michigan. Misc. Publ. Univ. Mich. Mus. ZooL, 73: 1-83. Mearns, E. a. — 1907 — Mammals of the Mexican Boundary of the United States. Part /, U. S. Nat. Mus. Bull., 56: i-xv, 1-530. Miller, A. H.— 1946 — Vertebrate inhabitants of the pihon association in the Death Valley region. Ecology, 27 : 54-60. Mitchell, Alan L. — 1934 — Eastern extension of the range of Peromyscus mani¬ culatus bairdii. four. Mammalogy, 15: 71. Moulthrop, P. N. — 1938 — The prairie white-footed mouse in New York State. Lour. Mammalogy, 19: 503. Murie, Adolph — 1933 — The ecological relationship of two subspecies of Peromys¬ cus in the Glacier Park region, Montana. Occas. Pap. Univ. Mich. Mus. ZooL, 270: 1-17. Murie, O. J., and Adolph Murie — 1931 — Travels of Peromyscus. Jour. Mammal¬ ogy, 12: 200-209. Osgood, W. H. — 1909 — Revision of the mice of the American genus Peromyscus. North Amer. Fauna, 29: 1-285. Rhoads, S. N.-^1903 — The mammals of Pennsylvania and New Jersey. Philadelphia, Privately published: 266 pp. Sanderson, Glen C. — 1950 — Small-mammal population of a prairie grove. Jour. Mammalogy, 31: 17-25 " Stoner, Dayton — 1918 — The rodents of Iowa, lotva Geol. Survey Bull., 5: 1-172. Storer, T. L, F. C. Evans, and F. G. Palmer — 1944 — Some rodent populations in the Sierra Nevada of California. Ecol. Monogr., 14: 165-192, Sumner, E. B. — 1926 — An analysis of geographic variaton in mice of the Peromys¬ cus polionotus group from Florida and Alabama. Jour. Mammalogy, 7 : 149-184. Watson, Margaret L. — 1942- — Hybridization experiments between Peromyscus polionotus and Peromyscus maniculatus. Jour. Mammalogy, 23: 315-316. Wright, Sewall — 1943 — Isolation by distance. Genetics, 28: 114-138. THE NICOTINIC ACID REQUIREMENT OF DROSOPHILA MELANOGASTER AND ITS RELATIONSHIP TO THE BROWN EYE PIGMENT BERNARD WORTMAN and ROBERT P. WAGNER Genetics Laboratory of the Department of Zoology The University of Texas INTRODUCTION The eye color of wild type Drosophila melanogaster is due to the presence of two pigments, red and brown. The exact chemical structures of these pigments are not known, although the brown pigment in particular has been studied extensively both with regard to its structure and its bio¬ synthesis. According to Goodwin and Srisukh ( 19 5 0) and Goodwin (1950) the brown pigment of Drosophila is very similar if not identical to the reddish-brown pigments found in other insects, having a substituted pyrrole and haempyrrole in its molecule. The biosynthesis of the brown pigment has been partly elucidated in Drosophila (Ephrussi 1942a, 1942b; Kikkawa 1941.), and it is clear that the in vivo synthesis starts with tryptophane and proceeds through kynurenin and 3 -hydroxykynurenin. The immediate pre¬ cursors, which would presumably in part be derivatives of 3 -hydroxy¬ kynurenin, are unknown. This biosynthesis is of interest in connection with nicotinic acid which has been shown to have a similar biochemical origin in many organisms which are able to dispense with preformed nicotinic acid in their food. The rat (Mitchell, Nyc, and Owen 1948), the mold Netirospora (Bonner and Wasserman 1950; Haskins and Mitchell 1949), maize (Nason 1949), the pea plant (Galston 1949) and a number of other organisms. can apparently synthesize their nicotinic acid from trytophane going through some of the same intermediates as the brown eye pigment. In addition it has also been shown that a derivative of 3 -hydroxykynurenin, 3-hydroxyanthranilic acid is one of the more intermediate precursors of nicotinic acid, although it does not seem to be so for the brown pigment. The question naturally arises as to the existence of a relationship between nicotinic acid and the brown eye pigment in the metabolism of insects. Tatum (1939, 1941) has investigated the vitamin requirements of Drosophila melanogaster and found that vermilion flies require nicotinic acid, but he did not investigate the wild type requirement for nicotinic acid. Since the genetic block in vermilion flies is between tryptophane and ky¬ nurenin, one would expect them to be unable to synthesize nicotinic acid. It was the purpose of this investigation to determine the nicotinic acid requirement of the wild type and compare it to that of the vermilion. EXPERIMENTAL The vermilion strain taken from stock was crossed to Oregon R wild type and the homozygous vermilion recovered in the second filial generation used as the stock mutant strain in these experiments. Oregon R was used as the wild type. 34 1953, No. 1 March Nicotinic Acid Requirement of Drosophila 35 Eggs were collected from females of both strains, sterilized and trans¬ ferred to tubes of sterile basal medium (Wagner and Mitchell 1948) containing washed yeast and plus or minus the supplements: kynurenin; 3 -hydroxyanthranilic acid; nicotinic acid. In order to free the yeast of nicotinic acid, its amide, and coenzymes I and II, dried Brewer’s yeast was thoroughly washed with hot and cold distilled water and ethanol until the soluble yellow coloring was removed. The yeast residue was dried in 95% ethanol, resuspended in 100% ethanol and collected on a Buchner filter. The original yeast lost 20% of its dry weight during this process. Enzyme digested and water extracted samples of the yeast residue were microbiologically assayed for their nicotinic acid content (Williams 1942). In the case of the water extract of the yeast residue sample, 0.0024 ug of nicotinic acid per mgm was detected. In the case of the enzyme hydrolyzate of the yeast residue sample, it was found that there was a factor which would inhibit the growth of the assay organism. The inhibiting factor could be partly diluted out and a much lower assay value obtained. In spite of the difference in the assay values, the essential fact remained that there were subminimal growth inducing amounts of nicotinic acid present in the yeast residue. The effectiveness of the growth factors was measured in terms of mean hours of larval life; percentage of pupae produced from the larvae; per¬ centage of adults emerging from the pupae. The results from supplementing the basal medium with various con¬ centrations of nicotinic acid are given in Table 1. Kynurenin and 3 -hydro¬ xyanthranilic acid were both ineffective in inducing growth in the absence of nicotinic acid. TABLE 1 THE GROWTH OF OREGON R AND VERMILION FLIES ON VARIOUS CONCENTRATIONS OF NICOTINIC ACID Nicotinic acid in ug/ml 0.0 0.05 0.5 1.0 3.0 5.0 Oregon R, Wild Type 10.0 15.0 Mean hours of larval life no no growth growth 328 267 218 208 196 178 Per cent pupation 5.1 28.0 53.0 54.0 92.0 74.0 Per cent adults 0.0 13.0 16.0 13.0 9.0 10.0 Vermilion, Mutant Mean hours of larval life no no growth growth 309 251 225 174 132 148 Per cent pupation 4.6 10.0 24.0 55.0 61.0 60.0 Per cent adults 0.0 0.0 11.0 4.0 5.6 4.8 36 The Texas Journal of Science 1953, No. 1 March DISCUSSION The data show conclusively that wild type requires a preformed source of nicotinic acid to be present at about the same level of concentration as vermilion in order to complete development on the medium used. None of the nicotinic acid precursors tested, kynurenin or 3-hydroxyanthranilic acid, showed nicotinic acid activity. It may be concluded that Drosophila has lost the ability to synthesize nicotinic acid even though it continues to be able to synthesize some of the natural precursors. It is also highly probable that this is true for a great many other insects as well, since most insects which have been investigated for their nutritional requirements have been shown to need nicotinic acid. The existence of a pattern of biochemical evolution is indicated which involves the utilization of an original "primitive” pathway of biosynthesis for other ends, in this case eye color pigment, once the need for the original required compound is met by preformed sources in the natural food substrate. When the insects first arose they may have been able to synthesize nico¬ tinic acid, but living in an environment abundant in nicotinic acid provided by microorganisms, etc., there was no strong positive selection for the ability to synthesize it. Therefore the chain of reactions involved in producing it from tryptophane became available for the synthesis of other compounds, such as brown pigment. The ability to synthesize this compound is now selected for, since it is involved in vision in all insects as well as providing body pigment in some. Such a scheme as described above may be involved in the evolutionary development of many biochemical pathways concerned with the production of compounds such as pigments, etc., which cannot be obtained from the environment in the preformed state, but must be synthesized in situ. The origin of these pathways is not explainable by, the Horowitz (1945) hypo¬ thesis alone. In that hypothesis the synthetic pathways are assumed to develop backwards from the original required nutrilite obtained from the environ¬ ment. But their origin is explainable if one assumes that the backward development of chains of reactions occurred first from nicotinic acid, and other similar metabolites; and then when the original required compound again became more abundant, the reaction chains, instead of being com¬ pletely abandoned, were used to produce different end products. LITERATURE CITED Bonner, D. M., and E. Wasserman — 1950 — The conversion of N’-"' containing indole to niacin by niacin-reqairing strain 39401 of Neurospora. J. Biol. Chem. 185: 69. Ephruhssi, B. — 1942a — Chemistry of "eye-color hormone’’ of Drosophila Quart. Rev. Biol. 17: 327. - 1942b — Analysis of eye color differentiation in Drosophila. Sym. Quant. Biol. 10:40. Galston, a. W. — 1949 — Indoleacetic-nicotinic acid interaaions. Plant Physiol. 24: 577. Goodwin, T. W. — 1950 — Biochemistry of locusts 4. Biochem. J. 47: 554. Goodwin, T. W., and S. Srisukh — 1950 — Biochemistry of locusts 3. Biochem J. 47: 549. 1953, No, 1 March Nicotinic Acid Requirement of Drosophila 37 Haskins, F. A., and H. K. Mitchell — 1949 — Evidence for a tryptophane cycle in Neurospora. Proc. Nat. Acad. Sci. 35: 500. Horowitz, N. H. — 1945 — On the evolution of biochemical synthesis. Proc. Nat. Acad. Sci. 31: 153. Kikkawa, H. — -1941 — Mechanisms of pigment formation in Bomhyx and Drosophila. Genetics 26: 587. Mitchell, H. K., J. F. Nyc, and R. D. Owen — 1948 — Utilization by the rat of 3-hydroxyanthranilic acid as a substitute for nicotinamide. /. Biol. Chem. 175: 433. Nason, A.— 1949 — Existence of a tryptophane-niacin relationship in corn. Science 109: 170. Tatum, E. L. — 1939 — -Nutritional requirements of Drosophila melanogaster. Proc. Nat. Acad. Sci. 25: 490. - -1941- — Vitamin B requirements of Drosophila melanogaster. Proc. Nat. Acad. Sci. 27: 193. Wagner, R. P., and H. K. Mitchell — 1948 — An enzymatic essay for studying the nutrition of Drosophila melanogaster. Arch. Biochem. 17: 87. Williams, R. J.— 1942 — Studies on the vitamin content of tissues II. Univ. Texas Publication 4237: 9. AN EXPERIMENTAL APPROACH TO THE ENIGMA OF TUMOR SUSCEPTIBILITY AND GROWTH BASED UPON INDIVIDUAL METABOLIC PATTERNS ROY B. MEFFERD, JR..* AND JOHN B. LOEFER+ Southwest Foundation for Research and Education, and Trinity University, San Antonio, Texas The days when optimistic and confident predictions were made that a solution to the cancer problem was imminent and that a cure would soon be available have passed. The chemotherapeutic approach has been disappointing. More and more it is realized that this complex problem must be resolved into its components and each in turn intensively studied. Such information, when assembled, may provide us with techniques and data to investigate further and enable us to understand and possibly control this "disease.” In no field of research can it be said with greater truth that nothing new exists under the sun. Many theories exist, but a solution is yet to be found. The writers are of the belief that many of the older observations may be correct, but should be checked by means of more critical technical procedures and that theories should be evaluated in the light of more recent information. Some aspects of the problem have been subjected to close scrutiny, with the results usually indicating that similarities exist between cancerous and non-cancerous tissue (Greenstein, 1947, Chapter 8; Krebs, Krebs, and Beard, 1950; Carruthers and Suntzeff, 1951). Similarity in chemical composition and behavior, and low antigenicity of tumor tissue for its host, indicate that neoplastic cells are probably not disease entities distinct from other host cells, but actually are normal cells which for some reason have exceeded the local bounds of restraint exerted upon them by hormonal or other control me¬ chanisms, or which have been forced into accelerated growth by the local production of some unusual compound, and which have accordingly "gone wild.” As Nicholson (1931) pointed out, "Every tumor— like every physio¬ logical organ — is truly congenital and truly acquired, whether it arises in an embryo as a reaction to an unknown stimulus, or in a centenarian as a reac¬ tion to X-rays, soot, tar, or what not. For the reaction is innate in either case and therefore, congenital and entirely physiological; the stimulus alone is extraneous to the reacting part, acquired and pathological.” Rous (1947), in an excellent survey, stated, "Perhaps the largest step forward of the last few years has been the very gradual comprehension, gained incidentally to the experimental production of tumors, that cancer is not a separate neo¬ plastic entity, does not stand off by itself, but is merely one amongst the immense group of the true neoplasms, all these being expressions of a single general principle, the neoplastic principle as one might call it, however widely they differ in cellular make-up.” * Post-Doctoral Fellow in Cancer Research of the Damon Runyon Memorial Fund. I- Present address: ONR Branch Office, Pasadena, Cal. 38 1953, No. 1 March Tumor Susceptibility and Growth 39 Based upon the well-known fact that totipotent cells are distributed throughout the soma, Krebs et aL (1950) have advanced the hypothesis that these cells, probably due to the influence of steroid hormones, undergo meiosis to form trophoblasts which then behave as they do in their normal environ¬ ment during pregnancy. It is known that normal rabbit trophoblasts devour uterine tissue when the normal control mechanisms are disrupted upon trans¬ ferring both to tissue culture (Maximov, 1925). Regardless of the initiating cause of neoplastic growth, it seems apparent than any stimulus which will disrupt the normal control mechanisms locally may, if of proper quality and quantity, induce hyperplasia in the area in¬ sulted. It is recognized that this insult may actually consist of several sequential separable phases (Rusch, 1950). It is well known that certain carcinogens, e.g., 20-methylcholanthrene, if properly applied, will induce neoplasms in virtually any locality, and therefore, of any nature, including such diverse expressions as epithelioma, leukemia, and glioma (Hartwell, 1951). Such diverse agents as radiations, certain viruses"' and widely differing chemical compounds will induce neoplasia of many types, or of identical types, and they all have the property of initiating irritating or inflammatory reactions which undoubtedly disrupt the normal control mechanisms (Men- kin, 1951). The inflammation, when of a certain type, and when of sufficient duration, might invoke the elaboration of ill-defined hormones, or cause existing ones to accumulate. Somatic mutations may play a significant role. In a manner similar to the way in which carcinogens induce neoplasms, common mutagenic agents produce non-specific mutations at given loci. Some mutagens, however, are also carcinogenic. It is not difficult to visualize that the production of a somatic mutation in a cell would modify a gene controlling the production of some antigenic substance, such as a certain enzyme, but which has been modified to such an extent as to render it foreign and, therefore, antigenic to the host. The antibodies formed in response to this antigenic stimulus would react with the antigen, i.e., with the modified enzyme molecules and cause an anaphylactoid reaction (Opie, 1929). The resulting inflammation might, in a few rare cases, act as a trigger to invoke the hyperplasia preceding neoplasia, as does the inflammation set up by the presence of a non-mutagenic carcinogen, or of a certain virus (e.g., in the Rous Carcinoma). Once neoplasia has commenced, the surrounding tissue responds with ill-defined resistance patterns, and the neoplastic tissue may be overwhelmed, contained, or practically unaffected. Only in the latter case will a gross inspection reveal a palpable tumor. It must be obvious that numerous loci of neoplasia, because of their very smallness, or because they already have been overwhelmed, are never recognized. Even by means of a thoroughgoing microscopic examination many could be overlooked, and hence the determination of induced or spontaneous tumors is subject to a high percentage of error. It is likewise impossible to determine the exact time of origin or initiation of growth of such tumors. A palpable tumor is a neoplastic growth of considerable potency, since it has not only established itself, but has been able to sustain a rapid rate of growth for a considerable period of time. Under these conditions, it is impossible to investigate criti¬ cally such matters as the role of nutrition on the incidence and growth of Russell and Wynne (Am. J. Med. Sd. 222:485-493, 1951). 40 The Texas Journal of Science 1953, No. 1 March tumors. Only when fragments of palpable size are implanted in the host, and their course of development or regression is followed by direct observation, can such experiments be successfully conducted." "' Takano and Huggins (Cancer Research 12:834-837, 1952). Regardless of the origin of the neoplasm, however, it is well recognized that resistance mechanisms of a much broader nature than those observed in classical immunology are immediately elicited. It is with the sum total of these forces that our investigations have been concerned. TUMOR IMPLANTATION One of the unique properties which has been ascribed to neoplastic tissue is its autonomy (Greene, 1951); yet, it can be demonstrated with a given tumor and within a closely bred strain of host animals, that some indi¬ viduals are resistant either to the induction, implantation, or support of the tumor. Most investigators have employed for experimental study tumors which could be successfully implanted and cultured in all animals of a strain. Investigators often misinterpret such performance as resulting from the autonomy of the tumor, when in reality it is conditioned by the resistance level of the host strain and of individuals within the strain, determined by their genotypes, and by the non-antigenicity (non-foreignness) of the tumor for the host. A tumor which is autonomous seems in some respects to be comparable to the perfectly adjusted parasite. Such a parasite is so equilibrated with its host that it exercises no inconvenience except for space requirements and nutrients. There is little or no detectable immunological response. For all intents, it is not foreign to the host’s tissues. During the growth of the tumor, tremendous population pressures (Braun, 1946) are established. Cells of lower viability, vitality, growth rate, or potentialities will soon be in the minority. This selection process is recognizable as an increase in malignancy and autonomy. The autonomy results from the selection during growth of cells less and less foreign to the host. The more nearly the proteins of the tumor are identical with those of the host, the more autonomous the tumor appears. Transplanted to a foreign strain, it elicits a more intensive response, since there more of its proteins are foreign and therefore, antigenic. If transplanted to a different host species, it is only the rare tumor which can tolerate this response, and increasingly so as the species are more distantly related (Towbin, 1951). We have dem¬ onstrated this fact lucidly with a transplantable rat fibrosarcoma in four different inbred strains of rats (Loefer and Mefferd, 1953 ). In one strain the tumor implanted in almost 100 per cent of the animals, while in an¬ other only 39 per cent did so. Since aliquots from a single tumor were used throughout and were controlled, only the relative resistance forces were measured. The results of quadruple inoculations from four different tumors of the fibrosarcoma within one strain (Mefferd and Loefer, 1952a) revealed the highly significant fact, speculated upon by Tannenbaum (1947), but not previously experimentally established, that these resistance mechan¬ isms extend to a determination of a successful implantation, as well as to the subsequent growth of the implant. The injection of the tumor fragment by means of a trocar initiates a typical inflammatory reaction (Murphy, 1926; Menkin, 1951). The im¬ mediate response is an infiltration by leukocytes, mostly neutrophils, and a * * Since going to press some of these problems have been discussed by Talalay, Takano 2nd Huggins (Cancer Research 12: 834-837, 1952). 1953, No. 1 March Tumor Susceptibility and Growth 41 congestion of the area, limiting mobility of elements in the area. A great deal of serum, lymph, and other highly nutritious material accumulates in the area. The implant is not impeded to any great extent, and continues to grow because the neutrophils are relatively ineffectual in hindering it (Gay and Morrison, 1923), and furthermore, there is no strong antibody response, since the proteins of the tumor are relatively non-foreign to the host. Nutri¬ tional factors in such a situation would not appear to be limiting. The success of the implantation will depend, therefore, upon what rapidly mobilizable defensive forces the host can elicit, and upon factors immediately affecting them, such as the lymphopenia and lowered antibody response following a pyridoxine deficiency (Stoerk, 1948). Exposure to ioniz¬ ing radiations causes a marked leukopenia {e.g., Henkel, et al., 1932), in¬ hibits the production of antibodies (Hektoen, 1915), lowers the resistance to infectious diseases to such an extent that normal saprophytes may initiate a septicemia, and enhances the takes of homologous skin grafts (Dempster et al., 1950) and tumors (Toolan, 1951). Probably the mustard gases would likewise enhance transplantations, since they exert similar effects as X-rays (leukopenia, lowered antibody production, cf. Rhoades, 1946). A low order of acquired immunity may be developed by host-animals for a few tumors, probably of a type for which immunological tests have not yet been perfected (Aptekman, 1947; Loefer and Mefferd, 1952b). Since tumor cells are actually largely of non-foreign composition, unless transplanted to a foreign strain, it is not surprising that so little success has attended efforts to demonstrate acquired immunity.'*' The second response, coming in about a week, involves the elaboration of antibodies to neutralize any foreign antigens which might be present (undoubtedly few, depending upon the degree of "autonomy” of the tumor) and the infiltration of monocytes and lymphocytes. These encircle the im¬ plant and tend to contain or destroy it (Murphy 1926; Algire, 1947; Wil¬ liams, 1951). Murphy has pointed out that these resistance forces are actually a relatively constant quantity. If this is the case, it is quite possible for such forces to destroy, or neutralize, a certain rather definite number of cells in any implant, regardless of its size. The size of the implant, therefore, becomes critically important. If it be assumed that the total defensive forces can neutralize 1x10^ cells in an implant, then an implant having 2 x 10‘' cells would have great difficulty establishing itself since one-half of its cells are neutralized repeatedly,'*' On the other hand, an implant containing 1x10^ cells would hardly be affected. Even if it were assumed that 90% of all cells in an implant are destroyed from a combination of trauma and defensive attack, a similar situation still prevails, as far as survival of the graft is concerned. Thus it may be seen that a kind of growth momentum exists in a tumor. Even if all cells are growing at identical rates, the larger the number present the better the tumor can fare in the "soil” of the host. Apparent lag periods or latency following induction or implantation may be explained as being due to the interval required for the unneutralized neoplastic cells * Several reviews, which appeared since this paper went to press, by Snell (Cancer Research 12:543-546, 1952), Barrett (ibid. 535-542) and Hauschka (ibid. 615-633) have emphasized this point and summarized the data on immunogenetics as related to tumor immunity and resistance. The role of genetic control of immunity factors, e.g., the histocompatibility-2 allelic series of mice and the interplay of genetic forces between the host and tumor in these respects, is clear. 42 The Texas Journal of Science 1953, No. 1 March growing at either a constant or variable rate, to gain momentum (number of cells X rate of growth) sufficient to overcome the defensive forces of the host. NUTRITION AND TUMOR RESISTANCE It is obvious that forces other than those just described are also operative in the expression of total resistance, since this resistance can be altered signifi¬ cantly by non-specific treatment of the host prior to implantation. We have demonstrated several of these alterations, involving such matters as the total number of implant cells required (Loefer, Mefferd and Nettleton, 1952), age of host (Loefer and Gilles, 19 51a), age of animal bearing the stock tumor (Loefer, 1952), and the existence of acquired immunity factors (Loefer and Mefferd, 1952b). Sabine and Olitsky (1938) have demonstrated that during host maturation, barriers quite unrelated to humoral immunity develop, which block in adult animals the routes of dissemination of infec¬ tious disease which are possible in young animals. Sabine (1941) demonstra¬ ted that nutritional deficiencies prevented or retarded the appearance of some of these natural barriers. The close relationship of rat implantation- susceptibility of a fibrosarcoma to age (Loefer and Gilles, 1951a) with that of infectious diseases is striking, as is also the susceptibility to ionizing radiation (Abrams, 1951). Of very great significance was the discovery, suspected since ancient time, that caloric restriction lowers the growth of spontaneous tumors (Rous, 1914). Tannenbaum (1947) demonstrated this clearly in leukemia and in 8 spontaneous or induced tumors. Friedman et al., (1952) showed that crowd¬ ing of Drosophila melanogaster larvae inhibited the penetrance of the ebony^^ pigmented tumor stock through the creation of a nutritional deficiency, probably in the yeast required for growth. Unfortunately the use of spontaneous or induced tumors precludes the extension of observations to tumor initiation or implantation, since the presence of a tumor can be ascertained only after considerable growth has occurred, and therefore it is not possible to determine the number of tumors which arose, many of which probably never reached detectable size. The use of a transplantable tumor, with techniques as developed in this laboratory, enables one to investigate resistance to tumor implantation as well as growth. That the resistance mechanisms to implantation were strongly influenced by nutritional factors was demonstrated by supplementation of the diet with pyridoxine (Loefer, 1951) and thymic extract (Loefer and Gilles, 1951). This treatment significantly enhanced implantation while a converse effect was noted following treatment with supplementary phenylalanine (Loefer and Mefferd, 1952a). As pointed out above, these effects are probably not the result of direct action upon the tumor cells. Resistance is thus a relative factor depending upon many variables, such as size of inoculum, age of host and donor animals, and significantly, the nutritional state of the animal. It is well known (Anderson and Fraser, 1934; Cannon, 1942; Cottingham and Mills, 1943; and Keys et ah, 1945) that classical immunity is affected by nutrition, but that malnourishment often plays a much greater role than an improvement in nutritional state. As * The results of Talalay et at. {vide supra) actually confirm this with respect to incidence for even a two-fold change in inoculum size. 1953, No. 1 March Tumor Susceptibility and Growth 43 Clark et aL, (19495 PP* 122-127) pointed out, the evidence is clear that the typical clinical picture of several virus diseases can be markedly altered by a variety of dietary deficiencies. By using a sufficiently large tumor fragment to overcome the implant¬ ation-resistance mechanisms, the influence of various factors upon growth may be investigated. We (Mefferd and Loefer, 1952) have demonstrated, within experimental limits of error, that the nutritional state of animals at the time of implantation may exert a significant influence upon the subse¬ quent growth of the tumor. A caloric restriction induced by injecting a competitive analog of riboflavin (isoriboflavin) into the future host-animal resulted in marked effects upon the growth of the tumor. It must be observed that it is impossible to create a single vitamin deficiency without so altering the metabolism of the animal as to yield an unintentional caloric restriction. The common tendency to average results obtained from experiments of this nature and to neglect a sequential treatment of the data in a manner which offers a possibility of detecting possible trends has undoubtedly masked many significant facts in the past. A consistent tendency in several small series may be more revealing than the results of a single large experiment, as these experiments demonstrated. A correlation was found between the rate of weight-loss in the host and size of tumor which developed. The greater the loss in weight, the larger the tumor grew. Likewise, in the control group, the animals gaining at the greatest rate supported the largest tumors. This is indicative of the existence of a more complex relationship between innate resistance, and nutrition (including related factors) than has been held previously. Resistance forces apparently play an important, yet a relatively constant (quantitative) role, being primarily cellular forces (Murphy, 1926, p, 32). It has been repeatedly demonstrated that control of tumor growth has seldom been achieved by specific treatment of the host, for the tumor will grow even at the expense of the host (White and Belkin, 1945; Loefer, 1952a). In view of the role of nutrition in immunity mechanisms and of the previously cited cases of its effect upon tumor implantation and growth, it seems clear that nutrition plays important direct as well as indirect deep- seated roles, altering innate resistance as well as such factors as the stroma- inducing capacity of the tumor, and hormonal balance of the host. That hormones, per se, exercise specific effects has been established (Huggins and Hodges, 1941). It thus appears that the apparent resistance both to implant¬ ation and subsequent growth is actually a composite of several interdependent factors."' We have suggested that tumor growth is regulated as a result of a shifting ratio between nutrition (including related factors) and resistance. INDIVIDUAL METABOLIC PATTERN APPROACH Beadle (1947) and the modern school of biochemical geneticists have laid the theoretical basis, and the brilliant concepts of R. J. Williams (1951, pp. 7-21) the modus, operandi, for attacking the problems of the funda¬ mental nature of resistance to neoplastic growth. The development of paper chromatographic procedures in the last few years permits rapid analytical studies to be made on the constituents of bio¬ logical fluids of individuals, particularly on such materials as amino acids. * In a recent paper Talalay, Takano and Huggins (Cancer Research 12:838-843, 1952) discuss some of the nutritional and hormonal factors involved. 44 The Texas Journal of Science 1953, No. 1 March purines, pyrimidines, nitrogen degradation products, sugars, and inorganic substances. The composite picture presented by such data reflects the meta¬ bolic pattern of the individual studied. Studies on biological fluids of rats and men have shown that there are very striking and consistent differences in the qualities and quantities of substances occurring in the body fluids of indi¬ vidual inbred animals even when on identical diets. To quote R. J. Williams (1951, p. 9) . . differences observable between individuals are often gross and require no hair-splitting refinements to detect. Corresponding values ob¬ tained from different individuals often differ not by 10 or 20 percent, but by as much as several hundred percent.” For example, Reed reported {vide supra, Table I, p. 140), an analyses made upon pooled samples (7-11 daily speci¬ mens in each case) showed that the amount of phosphorus excreted in the urine of a number of individuals belonging to a single strain of highly inbred Wistar rats ranged from 0.043 to 0.595 mg/mg creatinine — almost a 14- fold difference. Not only does the typical excretion pattern vary within a given strain, but it also varies with the strain of rat used. Thus, with respect to taurine, Reed reported {vide supra, F'igure ii, p. 147) that the Fischer 344 strain excretes several hundred times as much as the combined average of the six strains they used, whereas the Iowa 6 5-76 strain excreted less than 10 per cent of this average. To cite another comparison as regards lysine, the Iowa 2 5-32 strain excreted less than 10 per cent of the combined average, whereas the wistar W-l-B rat excreted approximately 2.75 times as much as the average. These workers have correlated peculiar individual metabolic patterns, particularly those involving vitamin deficiencies, with certain diseases, and they have shown further that these diseases (genetotrophic) may be success¬ fully treated by suitable dietary supplementation. They report the extremely encouraging conclusion, that even though a physiological condition rests upon hereditary roots, a nutritional attack may be successful. The rapidly growing literature relating to biochemical genetics establishes the theoretical basis for this conclusion. It is now generally recognized that genes control enzymatic reactions, which in their total expression establish the phenotype of the individual. Modification of the conditions surrounding the enzyme molecules, even though the quantity and specificity of the enzymes are basically gene-controlled, can result in a change in phenotypic expression. Thus, in an animal subjected to starvation the enzyme-substrate may be limiting to such an extent that, even though ample enzyme is present, the expression of its action, i.e., enzyme product formed, is identical with that of an organism in which the genotype is such that the quantity of enzyme itself is limiting. Likewise, in an animal possessing a gene which controls the production of an enzyme of low affinity for the substrate, or one which is limited in quantity, the phenotype can be altered by simply furnishing as a supplement the product of the reaction itself, assuming of course, that the substance is diffusible. It is conceivable that the phenomenon of tumor susceptibility is also a genetotrophic condition. Individual and strain variation, as regards both metabolic pattern and tumor susceptibility, may simply be an expression of metabolic pattern variation. Research directed along this line (Loefer and Mefferd, 1952, 1953) could contribute much to elucidate the nature of the "soil” in which a tumor can implant and grow. While numerous investigators 1953, No. 1 March Tumor Susceptibility and Growth 4S have sought to correlate a specific phase of altered metabolism, such as the nature of excreted steroids, with tumor susceptibility in individuals, there has been no study in which primary emphasis has been placed on the rela¬ tionship of the metabolic pattern to tumor susceptibility. As was the case with alcoholism (Williams et al., 1951), it may be necessary to scrutinize each individual pattern for factors related to susceptibility. The development of statistical concepts embodied in multiple factor analysis (Thurstone, 1947) has made possible an entirely new approach toward the analysis of complex biological data such as would be obtained from a thorough-going investigation of the metabolic patterns of susceptible and resistant individuals. By multiple factor analysis, the investigator should be able to determine those prime factors in the metabolic pattern which are correlated with resistance or susceptibility. The exact quantitative values of any individual determination are not important per se, but it is the relationship as a component of the pattern which is significant. One might desire, for humanitarian reasons, to make an immediate application of these procedures to human subjects. The complexity of the human subject, the time element, the impossibility of treating humans experi¬ mentally and of keeping them within the investigator’s ken, and above all the large expenditure in technical personnel and money, would seem to make it imperative that the exploratory investigations be made using experimental animals. Toennies ( 1952) has suggested an exploratory clinical study along roughly similar lines which would require about two million dollars. He proposes to determine at intervals only ten specific physiological character¬ istics for 5000 humans of different age groups for a period of five years. The records of those who develop cancer may then be scrutinized for possible physiological changes preceding the malignant expression of spontaneous tumors. The impossibility of selecting criteria known to be correlated with the development of cancer, with the concomitant danger of excluding possi¬ ble prime factors; the impossibility of differentiating between spontaneous tumors arising during the five-year period from those which were only latent; the failure to detect the early stages of neoplasia in many individuals during the period; the exceedingly poor experimental control as regards age, diet, activity, habits, etc.; and the necessity for chemotherapeutic and/or surgical treatment immediately upon detection would seem to distinctly favor a more critical and comprehensive approach utilizing inexpensive animals. The most feasible and promising approach seems to be through the use of a group of closely-bred, inexpensive animals, such as rats, which are large enough to enable collection of a sample of body fluid adequate for quantitative determination of 3 0 or more physiological characters. A tumor of well established growth characteristics must be used, /.c., the tumor cell- population should be thoroughly equilibrated by propagation through many transfers under carefully controlled conditions. The strain of inbred animals employed must necessarily have resistant members in order that two groups may be segregated, which vary as little as possible except in being resistant or susceptible to tumor implantation. Once the skeletal metabolic patterns are determined and the data analysed, it should be possible to determine the prime factors related to susceptibility, or to examine another group of physio- 46 The Texas Journal of Science 1953, No. 1 March logical characters. Application of these procedures, using the prime factors as determined in rats to human subjects, should effect considerable economy in time and money. The program offered here, we believe, could be accomplished in a rela¬ tively short time and at modest expenditure. Preliminary studies (Mefferd and Loefer, 195 3 ) in this laboratory have established certain differences in the patterns of resistant and susceptible animals. It is sincerely hoped that this communication may stimulate other laboratories to embark upon similar investigations. LITERATURE CITED Abrams, H. L. — 1951 — Influence of age, body weight, and sex on susceptibility of mice to the lethal effects of X-radiation. Proc. Soc. Exptl. Biol. Med. 76: 729-732. Algire, G. H. — 1947 — The transparent chamber technique as a tool in experimental tumor therapy. AAAS Monograph "Approaches to tumor chemotherapy,” pp. 13-66. Anderson, E. J. M., and A. H. H. Fraser — 1934 — The influence of nutrition on the natural immunity reactions of the blood and on skin reactions to bacterial toxin. J. Immunol. 27 : 1-16. Aptekman, P. — 1947 — A method of producing oncolysis in rats that conferred a certain immunity against homologous tumors. AAAS Monograph, "Approaches to tumor chemotherapy" , pp. 58-63. Beadle, G. W. — 1947 — Genes and the chemistry of the organism. Science in Prog¬ ress. 5th Series, Yale Univ. Press, New Haven, pp. 166-196. Braun, W. — 1946 — Dissociation in Brucella abortus: A demonstration of the role of inherent and environmental factors in bacterial variation. /. Bact., 5 1 : 327-349. Cannon, P. R. — 1942 — Antibodies and the protein reserves. /. Immunol. 44: 107-114. Carruthers, C. ,and V. SuNTZEFF — 1951 — A new common biochemical property of tumors derived from different tissues. Science 114: 103-107. Clark, P. F., L. S. McClung, H. Pinkerton, W. H. Price, H. A. Schneider, and W. Tracer — 1949 — Influence of nutrition in experimental infection Bact. Rev. 13: 99-134. Cottingham, E. and C. A. Mills — ^1943^ — Influence of environmental temperature and vitamin deficiency upon phagocytic function. /. Immunol. Al : 493-502. Dempster, W. J., B. Lennox, and J. W. Boag— 1950 — Prolongation of survival of skin homotransplants in the rabbit by irradiation of the host. Brit. J. Exptl. Path. 31: 670-679. Friedman, F., M. H. Harnly, and E. Goldsmith — 1952 — Nutritional factors af¬ fecting tumor penetrance in Drosophila melanogaster. Cancer Research 1 1 : 904-911. Gay, F. P., and L. F. Morrison — 1923 — Clasmatocytes and resistance to strepto¬ coccus infection. Studies in streptococcus infections and immunity, V. J. Inf. Dis. 33: 338-367. Greene, H. S. N. — 1951 — A conception of tumor autonomy based on transplantation studies: A review. Cancer Research 11: 899-903. Greenstein, j. P. — 1947 — Biochemistry of Cancer. Academic Press, Inc., Publ. New York. 389 pp. Hartwell, J. L. — 1951 — Survey of compounds which have been tested for carcino¬ genic activity. 2nd Ed. ^^149. U. S. Gov’t. Printing Off. pp. 248-317. Hektoen. L. — 1915 — The influence of the X-ray on the production of antibodies. /. Inf. Dis. 17: 415-422. Henkel, D. T., R. E. Brame, R. B. Mefferd, Jr., and J. B. Loefer — 1952 — Altera¬ tion of the blood picture by secondary X-radiation. Tex. Rpts. Biol. Med. 10(2):309-313. 1953, No. 1 March Tumor Susceptibility and Growth 47 Huggins, C., and C. V. Hodges — 1941 — Studies on prostatic cancer: 1. The effect of castration, of estrogen and of androgen injection on serum phosphatases m metastatic carcinoma of prostate. Cancer Research 1: 293-297. Keys, A., A. Henschel, H. L. Taylor, O. Mickelsen, and J. Brozek — 1945 — Experimental studies on man with a restricted intake of the B vitamins. Amer. J. Physiol, 144: 5-42. Krebs, E. T., Jr., E. T. Krebs, Sr., and H. H. Beard — 1950 — The Unitarian or trophoblastic thesis of cancer. Medical Record 163: 148-174. Loefer, j. B. — -1951 — Effect of pyridoxine and desoxypyridoxine on rat fibrosarcoma grafts. Cancer Research 11: 481-485. - - -1952 — Effect of age of the donor on development of rat tumor grafts. Cancer 5( 1): 163-165. — - -19523— “Growth of sarcoma in hypophysectomized rats. Cancer 5(1) : 161-162. Loefer, J. B., and N. G. Gilles — 1951 — Effect of thymic extract on a transplanted sarcoma in rats. Tex. Rept. Biol. Med. 9: 571-575. - — - 1951a— -Incidence of a transplanted rat fibrosarcoma relative to age of the host. Cancer 4(6): 1259-1262. Loefer, J. B., and R. B. Mefferd, Jr. — 1952 — Host susceptibility to tumor im¬ plants in relation to individual metabolic patterns, and its alteration. Proc. 2nd Infl. Cong. Biochem. Paris pp. 473-474. ■ - 1952a — Tumor susceptibility in relation to individual metabolic patterns. I. Alteration of host susceptibility to tumor grafts by nutritional means. Tex. Rept. Biol. Med. 10(3) :6l4-6l8. — — — '19526 — Tumor resistance phenomena. IV. Acquired resistance. Tex. Repts. Biol. Med. 10(4) : 849-854. - “1953 — -Tumor resistance phenomena. III. Host-susceptibility variation. Cancer 6: 184-187. - 1953a. Host resistance to tumor implantation, its alteration and relationship to the individual metabolic pattern. Experientia 9(3) : Loefer, J. B., R. B. Mefferd, Jr., and R. M. Nettleton, Jr. — 1952 — Tumor resist¬ ance phenomena. I. Experimental variables altering implantation and growth of a rat fibrosarcoma. Tex. Rept. Biol. Med. 10(3) :598-607. Maximov, A.^ — 1925 — Tissue-cultures of young mammalian embryos. Contrih. Embry- ol, Carnegie Inst. 16:47-113. Mefferd, R. B., Jr., and J. B. Loefer — 1952 — Tumor susceptibility in relation to individual metabolic patterns. II. Influence of the nutritional state of the host on tumor growth. Tex. Rept, Biol. Med. 10(3) :6l9-628. — —1952a- — 'Tumor resistance phenomena. II. Intrinsic resistance to tumor im¬ plantation. Tex. Rept. Biol. Med. 10 ( 3 ) :608-6l3. ... ... -1953 — Nitrogenous excretion of individual rats resistant or susceptible to a transplantable fibrosarcoma. Cancer Research 13(4): Menkin, V.—1951 — Newer Concepts of Inflammation. C. Thomas, Publ. Spring- field, Illinois. 145 pp. Murphy, J. B. — 1926-“The lymphocyte in resistance to tissue grafting, malignant disease, and tuberculous infection. Monograph jf21, Rockefeller Inst. Med. Res. New York. 168 pp. Nicholson, G. W. — 1931 — -An embryonic tumor of the kidney in a foetus. /. Path, and Bact. 34: 711-730. Opie, E. L. — 1929 — -Inflammation and immunity. ]. Immunol. 17: 329-342. Rhoads, C. P. — 1946 — -Nitrogen mustards in the treatment of neoplastic disease. J. A. M. A. 131: 656-658. Rous, P. — 1914 — The influence of diet on transplanted and spontaneous mouse tumors. J. Exptl. Med. 20: 433-451. Rous, P.^ — 1947 — Recent advances in cancer research. Bull. N. Y. Acad. Med. 23: 65-78. Rusch, H. P.-^ — 1950 — -Stages in cancer research. Tex. Rept. Biol. Med. 8: 207-214. Sabine, A., and P. K. Olitsky— 1938 — Influence of host factors on neuro-invasive- ness of vesicular stomatitis virus. /. Exptl. Med. 67: 201-249. 48 The Texas Journal of Science 1953, No. 1 March Sabine, A. — 1941 — Constitutional barriers to involvement of the nervous system by certain viruses, with special reference to the role of nutrition. /. Pediatrics 19:596-607. Stoerk, 14. C. — 1948 — Desoxypyridoxine. — Morphologic and functional changes in acute pyridoxine deficiency. Fed., Proc. 7: 281. Tannenbaum^ a. — 1947 — The role of nutrition in the origin and growth of tumors. AAAS Puhl. ’’Approaches to tumor chemotherapy.’' pp. 96-127. Thurstone, L. L. — 1947 — Multiple factor analysis; a development of the vectors of mind. Univ. Chicago Press. 535 pp. Toennies, G. — 1952 — Proposal for an experimental study of metabolic changes accompanying incipient human cancer. Scientific Monthly 74: 108-111. Toolan, H. W. — 1951 — Successful subcutaneous growth and transplantation of human tumors in X-irradiated laboratory animals. Proc. Soc. Ex-btl. Biol. Med. 77: 572-578. Towbin, a. — 1951 — The heterologous transplantation of human tumors. Cancer Research 11: 716-722. White, F. R., and M. Belkin — 1945 — Source of tumor proteins. I. Effect of a low-nitrogen diet on the establishment and growth of a transplanted tumor. Natl. Cancer Inst. J. 5: 261-263. Williams, R. J., et al — 1951 — Individual metabolic patterns and human disease: an exploratory study utilizing predominantly paper chromatographic meth¬ ods. Biochem. Inst. Studies IV, Univ. of Texas. Publ. tf^l09, 205 pp. Williams, R. G. — 1951 — The vascularity of normal and neoplastic grafts in vivo. Cancer Research 11: 139-144. NOTES ON THE CELL WALL OF HIGHER PLANTS RICHARD B. RYPMA Department of Biology A. & M. College of Texas Considerable confusion may arise from the implications and varied terminology in the literature resulting from any series of investigations of a problem. This may be particularly true when the literature has accumulated over a long period of time and from many sources with emphasis upon particular aspects of the problem. Historically the terms cell and cell wall, and the relationship of the two words, has presented a point for considerable controversy (Matzke, 1943). Robert Hooke in 166 5 applied the term cell to each of the small "cavities” that he observed in various vegetable materials. He was apparently aware that the content of many cells was in the form of juices or liquids; however, he probably did not recognize protoplasmic structure (Woodruff, 1939). In addition to Hooke, there was a host of observers and students who contributed to the knowledge of the fundamental living unit (Sachs, 1889). Leeuwenhoek (1685-1689) undoubtedly observed the cell wall; however, he apparently did not recognize it as a significant structure. Karling (1939) and Conklin (1939) have pointed out that several prior individuals stated the basic fundamentals of the cell theory; however, it is essentially the premises of Schleiden and Schwann that are usually emphasized by present- day biologists. These earlier investigators considered the compartments or pores as "cells”, and the cell walls or "interstitia” were not to be regarded as constituent parts, while the contents were largely ignored (Harvey-Gibson, 1919). Dujardin was probably the first to appreciate the importance of the cell content, and in 1 83 5 he applied the name "Sarcode” to this material. Some¬ time later, around 1844, Von Mohl announced that the slimy contents of the vegetable cell, the "primordial utricle”, was living substance and was the primary constituent of the cell. He gave this the name "protoplasm”, a term borrowed from human physiologists. With the discovery of the proto¬ plast, the major research emphasis was placed upon its activity, and the cell wall came to be regarded as a "lifeless excretion” of living substance (Sachs, 1889). At the present time, it seems convenient and justifiable to include the protoplast and its adjacent wall components as a biological unit. Sharp (1934) has pointed out that the cell wall is not regarded as a part of the cell proper, or protoplast, but usually as a product of the activity of the latter. If this is entirely the case, the cell wall should be no more than a non-living layer; however, as Eames and MacDaniels (1947) have noted, the layers of cell wall and even the middle lamella may contain living proto¬ plasmic material as long ts the protoplast remains vital. Meeuse (1941) has reviewed the literature establishing the presence of plasmodesmata in the walls of living cells and has noted the direct continuity of the protoplasts 49 The Texas Journal of Science 1953, No. 1 March JO and plasmodesmata, while some of the work of Heyn (1940) and the very nature of the framework of the wall provides evidence of intimate relation¬ ships between the wall and protoplasmic activities. Scott (1949) has stated that the "cell walls are heterogenous perforate structures, the pores of which are filled with living protoplasmic strands presumably capable of active metabolism”. Evidence of the unity of the cell wall and its adjacent proto¬ plast may be summarized therefore by: (1) the intimate relationship existing between the two, particularly during cytokinesis (Sharp, 1934) and during differentiation, and (2) the widespread occurrence of protoplasmic connec¬ tions (plasmodesmata) along with the possibility of the existence of other vital material within the framework of the wall. Strasburger has reviewed the literature on plasmodesmata up to 1901, and his criticism of the field gave greater clarity than any previous contri¬ bution. Plasmodesmata were first described by Tangl in 1879, although they were undoubtedly known to botanists before that time, Tangl had referred to these structures as "offene communicationen”; however, Strasburger’s adoption of the term '^plasmodesmen” for his "plasmaverbindungen” found rather general use and has evolved into the commonly accepted singular "plasmodesma” and the plural "plasmodesmata” (Meeuse, 1941). Numerous citations are found (Meeuse, 1941; Strasburger, 1901) establishing the presence of plasmodesmata in mosses, liverworts, ferns, and flowering plants, where they occur in all living tissues (Scott, 1949), includ¬ ing the meristematic regions (Meeuse, 1941). It has been definitely estab¬ lished that they are living strands of protoplasm and quite probably very significant in the function of the plant (Meeuse, 1941 a & b; Scott, 1949). The question of the development of these strands and their subsequent role in the life of the plant is still undetermined. CELL DIVISION AND THE CELL WALL Division of the cells of bryophytes and vascular plants ordinarily begins with the formation of the cell plate, which lies across the equatorial plane between the two daughter nuclei. Although the term phragmoplast is commonly used to designate the central spindle of the dividing figure and its subsequent laterally widened halo of fibrils, there are some grounds for objection to its use, since it is not a body or organ, but rather is a condition or period in the cycle of cell life (Bailey, 1920; Goldstein, 1925). The orientation of this spindle and the subsequent formation of the cell plate across it is apparently coincidental. Sinnott and Bloch (1939, 1940, 1941) have shown that in relatively large and highly vacuolate dividing cells the first visible evidence of the plane of division is the cytoplasmic configuration rather than any nuclear activity, and that this aggregate of cytoplasmic material forms a more or less continuous partition through which the cell plate will form. To this cytoplasmic plate they have applied the term phragmosome. The work of Bailey (1920), Goldstein (1925), and other authors (Bailey, 1920; Sinnott and Bloch, 1941, literature) seems to indicate that the situation is similar in younger cells. The fact that development of the middle lamella was closely associated with the cell plate phenomenon was established with the beginning of reliable investigations of the process of cell division. The theories which have been proposed to account for the origin of the middle lamella in general are of importance only from the historical standpoint and fall into three categories: ( 1 ) the theory, which was discarded early, that the cells were imbedded 1953, No. 1 March Cell Wall of Higher Plants 51 in a matrix of distinct material; (2) that the middle lamella is a septum formed by and common to adjacent cells; and (3) that when daughter cells are formed by cell division a substance is secreted in the space between them. The second concept was popular and strongly supported until the beginning of the 20th century. Treub and later Strasburger and other authors (Allen, 1901; Timber- lake, 1900) published accounts of the splitting of the cell plate and sub¬ sequent deposition of a middle layer between the two halves. Timberlake (1900) was apparently responsible for the earlier account that the cell plate was formed by the fusion of equatorial swellings of the spindle fibers, followed by the splitting of the cell plate to form the plasma membranes of the twin daughter protoplasts and subsequent appearance of the material of the middle lamella in the resulting cleft. In the more recent work of Becker and other authors ( 1938) it appears that the first indications of cell plate material may be in the form of minute droplets or vacuoles that, with increase in size, coalesce to form a continuous plate. Sharp (1934) supports this assumption and concludes that there is a local dissociation of twin protoplasmic phases, one forming a liquid cell plate and the other forming the plasma interfaces. Thus Becker defines cyto¬ kinesis as a dynamic dissociation of cytoplasm in a definite zone. The role of the fluid phase is still controversial. Becker concludes that these droplets solidify and become a part of the wall, while other authors feel that particles formed by the chromosomes or other protoplasmic parts migrate into this region (Becker, 193 8). Sharp (1934) points out that such dissociation has proven to be reversible in the living protoplasm of some forms. It must be remembered that cytokinesis by cell plates is a distinct pro¬ cess with characteristics wholly cytoplasmic; however, its fundamental mechanism is influenced by its relation with karyokinesis. Basically, then, we can conceive this process of dissociation as a separation of two bodies each with a greater cohesive force within themselves than for each other. This results in the separation of the protoplast into two derivative proto¬ plasts, each confined by the development of interfacial tensions of such magnitude that the protoplasm remains completely immiscible with its sur¬ roundings under normal conditions. The interfacial layers of the protoplast are termed the plasma membrane. THE CELL WALL In an attempt to clarify the confusion resulting from the terminology used and left unexplained by various investigators, Kerr and Bailey (1934) established the following criteria which have been generally accetped (Ander¬ son, 193 5 ; Foster, 1949; Bailey, 1938; Fames and McDaniels, 1947): (1) The middle lamella or intercellular material is an amorphous, isotropic (i.e., appears dark through crossed polaroid lenses) material, largely of pectic nature, and is the original cell wall material deposited between the proto¬ plasts; (2) the primary wall or cambial wall is the first anisotropic (i.e., visible through crossed polaroid lenses at different positions dependent upon the light) layer of the wall composed largely of cellulose and pectic sub¬ stances and capable of growth and extension, but may undergo reversible changes in thickness; (3) the secondary walls are any other wall components formed between the primary walls and the protoplast and limiting the potentiality for growth and enlargement of the cell (Fig. 1). 52 The Texas Journal of Science 1953, No. 1 March Upon the surfaces of the cell plate the primary or cambial walls develop as discrete morphological units which retain their identity throughout the growth and development of the cell (Kerr and Bailey, 1934; Eames and McDaniels, 1947). Between the two, physical and chemical changes occur which result in the establishment of a firm intercellular substance or middle lamella (Allen 1901; Timberlake, 1900). Early workers (Kerr and Bailey, 1934; Bonner, 1936, literature) recog¬ nized the presence of pectic compounds in the middle lamella, and some regarded it as a sort of cement between neighboring cells of a tissue. Kertesz (1951) states that the pectic substances are deposited as either one or two layers in the middle lamella by the plasma membranes and undergo changes in form, quantity and character during the development of the plant. And furthermore, he states that its mass may be increased by further pectin development or the material may be absorbed from the middle lamella. Bonner (1936), expanding earlier work, has shown that similarities exist between calcium pectate compounds and the middle lamella, and has further noted that certain differences in appearance of the cell wall may be due to variation in calcium content. Tupper-Carey and Priestley (1923) have maintained that the middle lamella is of a protein-pectin complex; however, it has been shown by Bonner (1936) that, although this is possible, such complexes in no way resemble the middle lamella. Kertesz (1951) has pointed out that the evidence presented in all cases is meager and that the role of any component should not be discarded. Considerable modification of the middle lamella may occur during enlargement of the cell. Carre (1922, 1925) and Tetley (1930) have shown that the pectins of the middle lamella undergo marked changes during the ripening of apple fruit. Early in the development of the fruit a middle lamella is evident by staining and seems to indicate a firm, even distribution FIG. 1. Diagram of the cell wall of organized plants, a — The compound cell wall composed of various lamella, b — The middle lamella, c — The primary wall, d — The innermost layer, e — the central layer, and f — the outermost layer of the secondary wall. 1953, No. 1 March Cell Wall of Higher Plants 53 of pectins, while later the staining becomes quite irregular. During the ripening process there is a continuous decrease in pectic materials with sub¬ sequent loosening of adjacent cells. Carre and Horne (1927) have described much the same happening in pears. Kerr and Bailey (1934, 1937), Bailey (1938), Harlow (1927, 1932), and Scarth, et al. (1929) have shown the presence of lignin in the middle lamella of woody plants probably in con¬ junction with pectins, cellulose, etc. It appears early in the cambial walls and intercellular material and becomes more intense with aging of the tissue. As lignification progresses the pectic content usually decreases. It has been suggested that pectins may be transformed into hemicelluloses and then into lignins directly or indirectly. Evidence exists for and against this conception (Kertesz, 1951; Buston, 193 5 ; Norman and Norris, 1930). Bonner (1936) and Kertesz (1951) have both emphasized the limita¬ tions of known staining techniques, particularly the old reliable ruthenium red (i.e., ammoniacal ruthenium oxychloride). The meagerness of our know¬ ledge of the pectic materials as they occur in plants and the limitations of morphological information, coupled with the complex structure of the pectins serves to support Bonner’s statement that the existing structures proposed are probably all "fundamentally in error”, as well as the reason for the multitude of contrary beliefs that have been presented. The first cellulose layer which is subsequently added, the cambial ivall of Kerr and Bailey (1934), by the protoplasts of adjacent daughter cells is singular in its capacity for growth and enlargement and in its character which allows reversible changes in thickness. It consists of an interjoining system of microfibrils of cellulose that are based upon a unit of no definite molecular weight, but rather upon long chains of varying length aggregated into bundles known as Micelles (Bonner, 1950). The Micelle concept was proposed by Nageli (1864) and subsequent investigation has served only to emphasize the essential accuracy of the larger part of his work. Seifriz (1934), Clark (193 0), Anderson (193 5 ), and others have shown that cellulose is composed of long chains of glucose residuces lying parallel to one another and oriented in the wall. Farr (1936), Farr and Eckerson (1934), and Sisson ( 193 5 ) have proposed that cellulose is present as a dis¬ continuous phase composed of cellulose units of microscopic size. Sponsler (1926, 1928) considers the cellulose to be oriented in a three dimensional lattice work composed of chains of glucose residues that lie parallel to and lengthwise the axis of the cell. The manner of the orientation of cellulose in the cell is still largely a disputed question. Considerable work has been carried out but most of it is contradictory (Bailey, 1939; Balls, 1923, 1926; Barrows, 1940; Farr and Sisson, 1934; Preston, 1949; Sisson, 193 5, Frey Wyssling, 1948; Sponsler, 1930; Stamm, 1930). Bonner (1950) has presented five possible orientations and noted that fluctuation exists between lamellae and within lamellae of the wall. Cellulose walls can be considered to consist of various numbers of parallel chains surrounded by some intermicellar substance and bound into a network formed by variable lengths of cellulose chain extending from one micellar aggregate to another, welding the whole into a coherent interlock¬ ing system. The micelles are the smallest structural units of naturally occurring cellulose and are apparently grouped together in many cell walls as long microfibrillar units parallel to one another or inclined to the long axis of the cell. 54 The Texas Journal of Science 1953, No. 1 March Cellulose is not known to occur alone in cell walls; however, the cellulose is probably responsible for the physical properties of the wall. Associated with the cellulose framework are substances such as lignin (Kerr and Bailey, 1934; Bailey, 1938; Harlow, 1932; and Ritter, 1928; Freuden- berg, 1932), pectic compounds (Kertesz, 1951), hemicelluloses (Bonner, 1950), cutin (Lee and Priestly, 1924; Priestly, 1943; Bonner, 1950), and suberin and mineral components (Fames and MacDaniels, 1947). The primary wall is characterized by the ability to undergo reversible changes. As Sponsler (1929) has pointed out, growth of the cell wall may be considered as three separate phases: (1) formation of the original or initial framework of cellulose, (2) increase in the surface area of the cell wall with subsequent increase in cell size, and ( 3 ) the increase in thickness of the walk Therefore, at the time of the laying down of a framework, the wall is endowed with the inherent ability to change in thickness and to change in surface area. Meyer and Anderson (1939) cite an example of marked elasticity in the case of mesophyll cells which may undergo rever¬ sible changes in volume of 30 per cent or more in response to turgor pressure changes. Heyn (1940) has defined three types of change which may occur within the wall: (1) elastic changes or the ability to undergo reversible changes in size or shape; (2) plastic changes or the ability to undergo permanent irre¬ versible changes in size or shape; and (3) extensibility or the ability to undergo changes in length. Thus reversible changes in the volume of the cell are due to elasticity of the primary wall, while irreversible changes are due to plasticity. Extensibility involves, therefore, the change in length of the cell actually affecting tangible measurements and may be due to either elastic change or plastic change. Enlargement of the surface area of the cell wall may be initiated and carried out in one or more of the following ways: (1) active increase in the growth of the cell wall as a result of the addition or intrusion of new cell wall material independent of other activities and resulting in the enlarge¬ ment of the wall surface; (2) elastic extension of the cell wall by turgor pressure with subsequent deposition of new cell wall material resulting in permanent extension of the cell wall surface; and (3) the possibility of plastic stretching involving reorientation of the fine structure of the cell wall and resulting in permanent change in the position of the particles. When enlargement of the cell has ceased, cell wall elaboration may continue for some time as the relatively massive secondary layers are formed. The major constituent (Bonner, 1950) in the secondary wall is cellulose, associated with lignin, hemcellulose, tannins, and reduced amounts of pec¬ tins. The process of lignification of secondary walls has been given particular attention by Harlow (1928, 1932), particularly with regards to location. Ritter (1928) and Harlow (1932) have reported that apparently chemical and physical differences exist in the lignins of various components of the cell wall. Bailey (193 8, 1940) has maintained that the developed secondary wall precludes any possibility of further growth or increase in the surface area of the cell. Therefore, regardless of stimulation, induced or natural, no resump¬ tion of growth will occur unless the protoplast escapes this sheath by one means or another. Bloch (1940) contends, on the other hand, that dediffer- 1963, No, 1 March Cell Wall of Higher Plants 55 entiation and subsequent growth may occur in the thickened lignified walls of the sclerenchyma cells of various monocotyledonous plants in response to the stimulus of wounding. Structurally and chemically the secondary cell wall is quite complex, and great tensile strengths have been reported. Meyer and Anderson (1939) have reported that the tensile strength of the flax fiber, for example, may be as great as 110 Kg. /mm" of wall area, as compared to spring hardened steel with a tensile strength of between 150-170 Kg./mm^. The structural pattern of the secondary wall is variable, but is somewhat similar to the primary wall and is often stratified and more or less lamellate (Bailey, 193 8; Bailey and Kerr, 1937) dependent upon the physical and chemical properties of the structure (Preston, 1949; Preston and Wardrop, 1949). The formation of the successive lamellae of the secondary wall may be by mtti,sstisception (i.e., the insertion of new micelles of wall substances between the network of those already present), or by apposition (i.e., the centripetal deposition of successive layers of lamellae). Foster (1949) has concluded that both are probably involved. EMBRYONIC CELL WALL NEW CELL WALL MATERIAL ADDED TURGOR PRESSURE I ELASTIC EXTE N SION DEPOSITION OF NEW MATERIAL TURGOR PRESSURE CHANGE IN ORIENTATION OF THE CELL STRUCTURE INCREASE IN SURFACE AREA OF THE CELL WALL FIG. 2. The three general possibilities offered as means of increase in the surface of the cell wall. 56 The Texas Journal of Science 1953, No. 1 March SUMMARY This paper is an attempt to convey some idea of the cell wall to teachers, and others alike, who are without adequate library facilities and must by necessity convey views to their students that are not necessarily in keeping with more recent developments. More important still, an attempt is made here to present a cross section of the available literature, hoping that a greater clarity may be gained through its use. Except as a survey of the literature, no contribution is made; however, it is hoped that this will bring new information to the group that has not had it available prior to this time. LITERATURE CITED Allen. C. E. — 1901 — On the origin and nature of the middle lamella. Bot. Gaz. 32: 1-34. Anderson, D. B. — 1935 — The structure of the walls of the higher plants. Bot. Rev. 1: 52-76. Bailey, 1. W. — 1920 — Phragmoscmes and binucleate cells. Bot. Gaz. 70: 469-471. - 1938 — Cell wall structure of higher plants. Ind. and Eng. Chem. 30: 40-47. - 1939 — The microfibrillar and microcapillary structure of the cell wall. Bull. Ton. Bot. Club 66(4) : 201-213. - 1940 — The walls of plant cells. A.A.A.S. Buhl. 14: 31-43. - and T. Kerr — 1937 — The structural variability of the secondary walls as re¬ vealed by lignin residues. Jour. Arnold Arboretum 18: 261-272. Balls, W. L. — 1923 — The determiners of cellulose structure as seen in the cell wall of cotton hair. Broc. Boy. Soc. London 95: 72-89. - 1926 — Measurements of the reversing spiral in cotton hairs. Broc. Roy. Soc. London. B. 99: 130-147. Barrows, F. L. — 1940 — Lamellate structure of cellulose membranes in cotton fibers. Contrib. Boyce Thompson Inst. 1(2): 161-179. Becker, W. A. — 1938 — Recent investigations, in vivo, on the division of plant cells. Bot. Rev. 4(8) : AA6-A12. Bloch, R. — 1940 — Wound healing in higher plants. Bot. Rev. 7(2) : 110-146. Bonner, J. — 1936 — The chemistry and physiology of the pectins. Bot. Rev. 2: 475-497. - 1950 — Blant Biochemistry. The Academic Press Inc. New York, New York. Buston, H. — 1935 — Observations on the nature, distribution and development of certain cell wall constituents of plants. Biochem .Journ. 29: 196. Carre, M. — 1922 — An investigat'on of the pectic constituents of stored fruits. Biochem. Journ. 16: 704-712. - 1925a — Chemical studies on the physiology of apples. Ann. Bot. 39: 811-839. Carre, M. — 1925b — The relation of pectase and pectin in apple tissue. Biochem. Journ. 19: 257-265. - and A. S. Horne — 1927 — An investigation of the behavior of pectin ma¬ terials in apples and other plant tissues. Ann. Bot. 41: 193-238. Clark, G. L. — 1930 — Cellulose as it is completely revealed by X-rays. Journ. Ind. and Eng. Chem. 22: 474-487. Conklin, E. G. — 1939 — Predecessors of Schleiden and Schwann. Amer. Nat. 73: 538-546. Fames, A. J., and L. H. McDaniels — 1947 — An Introduction to Blant Anatomy. 2nd Edition. The McGraw-Hill Book Co. Inc. New York and London. Farr, W. K. — 1936 — The chemistry of cellulose. Tex. Res. 6: 518-520. - and S. H. Eckerson — 1934 — Separation of ceiluose particles in membranes of cotton fibers by treatment with hydrochloric acid. Contrib. Boyce Thompson Inst. 6: 309-313. 1953, No. 1 March Cell Wall of Higher Plants 57 - — ^and W. A. SiSSON — 1934— X-ray diffraction patterns of cellulose particles and interpretation of cellulose dildraction data. Contrib. Boyce Thompson Inst. 6: 315-321. Foster, A. S. — 1949 — Practical Plant Anatom'^. D. Van Nostrand Company Inc. Toronto, New York and London. 2nd Edition. Freudenberg. K. — 1932 — The lelation of cellulose to lignin in wood, lourn. Chem. Ed. 9: 1171-1180. Frey Wyssling, A. — 1948 — The growth in surface of the plant cell wall. Growth 12: 151-159. Goldstein, B. — 1925 — A study of progressive cell plate formation. Bull. Torrey Bot. Club 52: 197-219. Harlow, W. H. — -1927 — The chemical nature of the middle lamella. N. Y. State College For. Tech. Pub. No. 21. - 1928 — Lignification in the secondary and tertiary layers of the cell walls of wood. Bull. N. Y. State College For. Tech. Pub. No. 24. - 1932 — Further studies on the location of lignin in the cell wall of wood. Am. Journ. Bot. 19: 729-739. Harvey-Gibson. R. J. — 1919 — Outlines of the History of Botany. London. Heyn, a. N. J. — 1940 — -The physiology of cell elongation. Bot. Rev. 6: 515-574. Karling, j. S. — 1939 — Schleiden’s contribution to the cell theory. Am-er. Nat. 73: 517-537. Kerr, T., and I. W. Bailey — 1934 — Structure, optical properties and chemical com¬ position of the so-called middle lamella. Journ. Arnold Arbor. 15: 327-349. Kertesx, Z. I. — 1951 — The Pectin Substances. Interscience Publishers. New York, and London. Lee, B., and J. H. PRIESTLY — 1924 — The plant cuticle. I. Its structure, distribution and function. Ann. Bot. 38: 525-545. Leeuwenhoek, A. — 1685-1687 — An abstract of a letter from Mr. Anthony Leeu¬ wenhoek. Fellow of the R. Society. Letter dated Delft, July 25, 1684. Phil. Trans. Roy. Soc. 15: 883-895. Matzke, E. B. — 1943 — The concept of cells held by Hooke and Grew. Science 98: 13-14. Meeuse, a. D. j. — 1941a — Plasmodesmata. Bot. Rev. 7: 249-262. - — 1941b — On the nature of plasmodesmata. Protoplasma 35: 143-151 Meyer, B. S., and D. B. Anderson — 1939 — Plant Physiology. D. Van Nostrand Co. Inc. New York, New York. Nageli. C. — 1864 — Uber den inneren Bau der vegetabilischen Zellmenbranen. Sitzber. Bay. Akad. Wis. Muchen 1: 282-323; 2: 114-171. Norman, A., and F. Norris — 1930 — The oxidation of pectins by Fenton’s reagent and its bearing on the genesis of the hemicelluloses. Biochem. Journ. 24: 402. Preston, R. D. — 1949 — The fine structure of the wall of the conifer tracheid III, Dimensional relationships in the central layer of the sceondary wall. Bio- chimica et Biophysica Acta 2: 370-383. - and E. NiCOLAi with R. Reed and A. Millard — 1948 — An electron micro¬ scope study of the celluose in the wall of Valonia ventricosa. Nature 162: 665. - and A. B. Wardrop — 1949a — The submicroscopic organization of conifer cambium. Biochimica et Biophysica Acta 3: 549-559. - and A. B. Wardrop — 1949a — The fine structure of the wall of the conifer tracheid IV. Dimensional relationships in the outer layer of the secondary wall. Biochimica et Biophysica Acta 3: 585-592. Priestly, J. H. — 1943 — The cuticle in angiosperms. Bot. Rev. 9: 593-616. Ritter, G. J. — 1928 — Composition and structure of the cell wall of wood. Journ. Ind. and Eng. Chem. 20: 941-945. Sachs, J. — 1889 — -History of Botany, 1530-1860. Engl. Trans, by H. E F. Garnsey, The Clarendon Press, Oxford. SCARTH, G. W., R. D. Gibbs and J. D. Spier — 1929 — The structure of the cell wall and the local distribution of the chemical constituents. Trans. R^oy Soc. Can. Sect. 5: 269-288. 58 The Texas Journal of Science 1953, No. 1 March Scott, F. M. — 1949— Plasmodesmata in xylem vessels. Bol. Gaz. 110(3): 492-495. Seifriz, W. — -1934 — The origin, composition and structure of cellulose in the liv¬ ing plant. Protoplasma 21: 129-159. Sharp, L. W —l9^A—lntroducHcn to Cytology, The McGraw-Hill Book Co. Inc. New York and London. 3id Edition. SiNNOTT, E. W.-— 1939— Growth and differentiation in living plant miristems. Proc. Nat. Acad. Sci. (U.S.A.) 25: 55-58. — — -and R. Bloch — 1940— Cytoplasmic behavior during cell division of vacu¬ olate plant cells. Proc. Nat. Acad. Sci. Wash. 26: 223-227. - — 1941a — Division in vacuolate plant cells. Amer. Journ. Bot. 28(3) : 225-232. - - — -194lb — The relative positYn of cell walls in developing plant tissues. Amer. Journ. Bot. 28(7): 607-616. Sisson, W. A. — -1935— X-ray studies of crystallite orientation in cellulose fibers. Natural fibers. Ind. and Eng. Chem. 27: 51-56. - 1941— X-ray studies regarding the formation and orientation of crystalline cellulose in ihe cell walls of Valonia. Contr. Boyce Thompson Inst. 12(3): 171-180. Sponsler. O. L. — 1926 — Molecular structure of plant fibers determined by X-rays. Journ. Gen. Phys. 9: 677-695. - — 1928- — The molecular structure of the cell wall of fibers. Amer. Journ. Bot. 15; 525-536. - 1929 — Mechanism of cell wall formation. Plant Phys. 4: 329-336. — — - 1930 — Orientation of cellulose space lattice in the cell wall. Protoplasma 12: 241-254. Stamm, A. J. — 1930 — -The state of dispersion of cellulose in cuprammonium solvent as determined by ultracentrifuge methods. Journ. Amer. Chem. Soc. 52: 3047-3062. Strasburger, E.— 1901 — Uber Plasmaverbindungen pflanzlicherzellen. Jahrb. Wiss. Bot. 36: 493-601. Tetley, U.-^ — 1930 — A study of the anatomical development of the apple and some observations on the pectic constituents of the w’all. Journ. Pomol. Hort. Sci. 8: 153-172. Timberlake, H. G. — -1900 — The development and function of the cell plate in higher plants. Bot. Gaz. 30: 73-154. 1900. Tupper-Carey, R. M., and J. H. PRIESTLEY— 192 3— The composition of the cell wall at the apical meristem of stem and root. Proc. Roy. Soc. London. B95 : 109-131. Woodruff, L. L. — 1939— Microscopy before the nineteenth century. Amer. Nat. 73: 485-516. ESTABLISHMENT AND UTILIZATION OF BULBOUS BLUEGRASS, POA BULBOSA L., IN NORTH TEXAS SUBSERES. 1. TAXONOMIC DESCRIPTION AND DEVELOPMENTAL MORPHOLOGY A. W. ROACH AND J. K. G. SILVEY North Texas State College INTRODUCTION Perhaps one of our most unusual grasses, bulbous blue grass {Poa biilbosa L.) diverges strikingly from common generic characters through morphological floral alteration. The compound panicle, which distinguishes it, nods when mature on a slender, few-leaved culm, and consists of a variegated "plume” of twisted, viviparous bulblets which have replaced the florets of the spikelet (Fig. 1, A). Quantitatively, this grass is of medium growth form and occurs usually in dense aggregates. While its developmental morphology is of technical interest, several ecologic characters indicate potential economic use in degraded range areas of North Texas. These are: (1) within areas of establishment, bulbous blue- grass occupies the more severe substrates of ruderal seres. Near Corvallis, Oregon, such a plasticity allows this grass to thrive in bare, sterile soils devoid of the more common annual, primary invaders; (2) a recognition of its adaptability and particularly its ability to compete with downy cheat grass (Bromus tectorum L.), which has replaced the native climax grasses in the arid intermountain ranges of the Great Basin, has led to extensive seeding programs in those areas by the U. S. Department of Agriculture (Stoddart and Smith, 1943). In a recent paper, Shinners (1948) has emphasized both the funda¬ mental principles governing establishment, migration, and eventual distribu¬ tional patterns of introduced plants and the definite benefit derived from many as components of the Texas flora. In a personal communication, he states that the introduced flora of Texas is exceptionally small, barely 3% of the total, compared with 17% in California and 20% in the Northwest, and that there is room for importation and study of ecological equivalents of possible economic use. Since published information on bulbous bluegrass is confined largely to floras, it is first the purpose of the authors to add observations in this paper to its known morphology, taxonomy, and phenology. Secondly a series of quantitative studies, to be published later, have been initiated, in view of its ecologic plasticity, to determine the feasibility of its use as a pioneer reactor on North Texas ranges. These autecologic studies will include statistical variations of quantita¬ tive growth form and life cycle in a range of habitats as explained by micro¬ climatic, edaphic, and biotic analyses. In addition, vegetative chemical analyses as expressions of forage values will be determined. 59 60 The Texas Journal of Science 1953, No, 1 March FIGURE 1. Morphology of Poa bulbosa L. Part A, mature plant; note bulbous base and altered panicle. Part B, normal spikelet; note the 5 florets with ciliate keels. Part C, leaf point of divergence; note unusual midfold of the ligule. FIGURE 2. Morphology of ihe altered spikelet Poa bulbosa L. Part A, initial elongation of the fourth lemma; Part B, pseudoembryo or fifth lemma; note "radicle” and "plumule”. Part C, initially ecized bulblet; note attenuation of lemmas into leaf blades; Part D, established bulblet; note swollen lemma bases and emergence of fifth lemma as culm. 62 The Texas Journal of Science 1953, No. 1 March DISTRIBUTION AND TAXONOMY Bulbous bluegrass, a native of Europe and a component of the Mediter¬ ranean complex of North American invaders, was introduced probably first into the Atlantic Coastal Plain and since inland. It is scattered throughout the meadows of Virginia and North Carolina (Hitchcock 193 5 ). In the continental grasslands formation, it has achieved an increasing distribution from Oklahoma north to Michigan and North Dakota and west across the Idaho-Montana saddle to the palouse prairies of the Pacific Northwest. Hitchcock ( 193 5 ) reported its introduction in and around Medford, Oregon, for cultivation; however, since that time it has escaped and is quite pre¬ valent throughout the western trough north to British Columbia and south into California. Poa bulbosa L. Sp. PL. 70, (Eur., As., Afr.) has been described as: culms closely tufted, bulbous at base, 3-6 dm. high; blades and sheaths glabrous, the former short 1-2 mm. wide; panicle narrowly ovoid, 5-8 cm. long; flowers replaced by small purplish bulblets about 2 mm. long, the glumes, lemmas, and paleae attenuate into green appendages 1-2 cm. long (Hitchcock 193 5 ; Peck 1941). However, many individuals may complete their life cycle without attaining more than a decimeter in height. The short blade is accentuatedly navicular, perhaps more so than in other species of the genus. In addition, bulblet formation is somewhat different, and the ligules are 2-3 mm. in length and have an usual midfold which may be unique (Fig. 1, part C). FLORAL ALTERATION AND LIFE CYCLE The entire spikelet or inflorescence unit, with the exception of the glumes, is uniformly differentiated into a single vegetative bulblet which usually disarticulates at maturity above the glumes. Rarely the florets of a few spikelets fail to differentiate and remain normal, and occasionally there are a few spikelets which are altered but fail to develop. Of the normal spikelets, Hitchcock ( 193 5 ) describes them as five-flowered whose lemmas are both webbed at the base and densely silky on the keel and marginal nerves. Most unaltered florets, however, are merely long ciliate on the keel with glabrous marginal nerves (Fig. 1, part B). During the course of alteration, the floral whorls do not develop first and then become converted, as previously thought, but rather the gynoecium, androecium, and paleae are never formed. In the young asexual floret, the fourth lemma elongates, is never ciliate on the keel, the nerves enlarge, and the internerves become dark purple (Fig. 2, part A). The third lemma, then the second, and finally the first, progressively change as the fourth changes, all becoming swollen and hard at their bases with reserve food. The fifth lemma is the "plumule” and produces the culm; whereas, a "radicle” as a separate or new growth is produced near the base of the third lemma, since the rachilla is greatly foreshortened over the normal condition, and erne’'" as the primary root. Poa bulbosa is a vernal grass, developing early with the main group of spring forbs. It grows rapidly and completes its growth within four weeks. At the initial emergence of the panicle, the leaves are vigorous but soon wither and the latter development takes place on just the slender, apparently naked culm. The young bulblets disarticulate either above or below the glumes and lie dormant until they receive sufficient moisture to sprout. 1953, No. 1 March Bulbous Bluegrass 63 During the fall of the first year the plant grows vegetatively and reaches full stature the following spring and produces a panicle. The bulbous base of the culm enlarges and bears the dead sheaths of the first year plant (Fig. 1, part A) . The evolution of the first-year plant is portrayed by the established bulblets of Figure 2. Part C illustrates the alteration of the lemma tips into sheaths and leaf blades with a ligule at the junction. In part D, the "plumule” of the fifth lemma has elongated as the culm, and the "cotyle¬ dons” of the first, second, and third lemmas have withered. Grateful acknowledgement is due G. T. Goodman, Curator of the Bebb Flerbarium of the University of Oklahoma for his loan of the follow¬ ing specimens: Fred Barkley, 3020, Salt Lake City, Utah; John Merkle, 690, Berrien Co., Michigan; G. T. Robbins, 2426, Pontotoc Co., Oklahoma; M. Bebb, 13 0, Lugano, Switzerland; A. A. Beetle, 173 5, Lake Co., California. LITERATURE CITED Hitchcock. A. S. — 1935 — Manual of the grasses of the United States. U.S.D.A. Misc. Pub. No. 200. Peck, M. E. — 1941 — A manual of the higher plants of Oregon. Portland, Oregon: Binfords & Mort. Shinners, L. H. — 1948 — Geographic limits of some alien weeds in Texas. Texas Geographic Magazine 12: 16-25. Stoddard, L. A. and A. D. Smith — 1943 — Range management. New York: Mc¬ Graw-Hill. THE THIAMINE CONTENT OF SELF-SELECTED DIETS OF COLLEGE WOMEN AS RELATED TO THE ENRICHMENT OF CEREALS^ FLORENCE I. SCOULAR AND ADA RUTH RANKIN School of Home Economics, North Texas State College With enrichment of white bread and all purpose flour in Texas, it has been assumed that the daily thiamine intake has been increased and that it is adequate for good nutrition. Charles Glen King, Scientific Director of the Nutrition Foundation (1948) says, "Laymen want to know in a simple way, that their food intake selected on a highly personal basis without too great sacrifice of cost, convenience or enjoyment is adequate to protect health with a reasonable margin to spare. One of the difficulties is the practi¬ cal problem of getting people to eat what scientists recommend on the basis of good evidence. Automatically, there are limitations involving education, cost, tradition, convenience and an element of pleasure. In the past too much reliance has been placed upon variety of intake. Merely changing food items from day to day does not give assurance of good nutrition. Variety within major groups of reliable foodstuffs, however, can afford protection together with enjoyment and reasonable economy.” In 1942 Lane and others determined the thiamine content of the average American diet, such as was consumed by the middle two-thirds or three-fourths of the population prior to the advent of enriched bread or flour and found it to be about 0.8 mg per 2 5 00 calories. This value is sub¬ stantially lower than previously supposed from the results of computations of Stiebeling and Phipard (1939). Furthermore, the foods used in deter¬ mining Lane’s average mixed diet probably offer a wider variety than is usually available to the individual. In our laboratory a long-time study of self-selected diets was instituted, using the home management house residence women who were willing to serve as subjects. By this arrangement the daily composite food was identical for all the individuals while the total individual intakes varied considerably due to the separate analysis of milk and the correspondingly varied intakes of beverage milk. The purpose of the present study was to determine the thiamine intake and the urinary excretion of young college women consum¬ ing self-selected diets containing enriched white bread and cornbread made with either enriched or unenriched cornmeal. PROCEDURE The daily thiamine intake and the urinary excretion of 22 young college women consuming self-selected diets were determined during five- day periods. The precautions and procedures of Holt and Scoular (1948) were used in collecting the food and excreta samples for analysis. A serving of each food from each meal similar in all respects to that eaten by the col- ’ Financed by Faculty Research Fund, North Texas State College, Denton, Texas. 64 1953, No. 1 March Thiamine Content of Diets 65 lege women was collected in weighed jars at the same time that the sub¬ jects were served at the table. The weight of the meal was determined before the food was macerated in a Waring Blendor and an aliquot taken from each meal to form the composite daily sample which was identical for all subjects. One-fourth glass of milk was collected daily in a similar manner, thus giving one homogenous milk sample for each five-day period. A record was kept of the number of glasses of milk consumed by each subject each day since this was the only variable in the daily food intake. After analysis suitable additions were then made to each individual’s total food intake to include the milk thiamine. All samples were refrigerated until analyzed. The diets were planned by the two groups of young college women living in the Home Management duplex at the time of the study. Both groups used the same menus for a five-day period, with each group pur¬ chasing its own food supply. All the bread and flour used by both groups were enriched. Each day a serving of cornbread was eaten at one of tlie meals. One group (S) used unenriched cornmeal while the other group (N) used enriched cornmeal^ in the making of the standardized recipe for corn- bread. Although the cornbread recipe had been standardized, the methods of cooking the other foods had not been and so varied with the individual cook’s experiences and techniques. The thiamine content of the food and urine was determined by using the Connor and Straub method (1944), with modifications from the As¬ sociation of Vitamin Chemists (1947) and Gyorgy (1950) in developing thiamine to thiochrome. TABLE l DETERMINED AND CALCULATED THIAMINE VALUES OF DAILY COMPOSITE FOOD SAMPLES Thiamine Content Determined Calculated Group S^ Group N- mg mg 1.06 2.26 1.87 1.14 0.90 0.89 1.07 1.18 1.30 1.07 1.70 0.74 1.73 1.00 1.13 0.41 0.51 1.87 0.82 0.84 0.89 0.74 0.65 1.30 0.70 1.08 0.74 1.00 0.91 1.13 0.33=^ 0.69-^ 1.08-^ Av. 0.92 1.07 1.18 iGroup S served unenriched cornmeal cornbread. ^Group N served enriched cornmeal cornbread. '"^Average of 5 days’ composite food supply. -Enriched cornmeal furnished by Texas State Nutrition Council’s Research Committee. 66 The Texas Journal of Science 1953, No. 1 March RESULTS AND DISCUSSION The thiamine content of the daily composite food samples is given in Table 1. All of the daily food samples were analyzed separately except for the five-day period represented by the last figure in the first two columns. These values, 0.3 3 and 0.69 mg of thiamine, are the average of a five-day period food supply, since it was not possible to keep these for separate analysis due to limited refrigerator space. For interest the calculated thia¬ mine values of the diets are also given in the same table. In comparing the two groups, S and N, it is apparent that while the same menus were pre¬ pared the inclusion of one serving a day of enriched cornmeal cornbread by group N did not give consistently higher daily values for this group, although the average of all such diets was slightly higher, namely, 1.07 as compared to 0.92 mg of thiamine for group S with the unenriched corn- meal cornbread. Both the enriched and unenriched cornbread diets varied greatly from the calculated thiamine values, sometimes being less and some¬ times more. It is necessary, however, to keep in mind that the calculated values with an average of 1.18 mg of thiamine for the composite food samples may not be correct. When values for combination dishes and salads were not available in published tables, the thiamine content was calculated, using the individual ingredients which usually disregarded cooking losses. It was previously stated that thiamine is destroyed in many cooking pro¬ cesses and that the methods used in preparation of the meals, with the ex- TABLE II AVERAGE DAILY THIAMINE INTAKE AND URINARY EXCRETION OF TWENTY-TWO YOUNG COLLEGE WOMEN Group Group N2 Period Subject Food Urine Composite Milk Total Subject Food Composite Milk Total Urine mg mg mg mg mg mg mg mg Study 1 Box 0.69 0.11 0.80 0.03 Bal 0.33 0.05 0.38 0.03 Mil 0.69 0.11 0.80 0.03 Man 0.33 0.11 0.44 0.04 McL 0.69 0.11 0.80 0.04 Pet 0.33 0.12 0.45 0.06 Sal 0.69 0.11 0.80 0.04 Eu 0.33 0.12 0.45 0.04 Whe 0.69 0.11 0.80 0.05 Br 0.33 0.13 0.46 0.05 Whi 0.69 0.11 0.80 0.03 Str 0.33 0.15 0.48 0.06 Average 0.44 0.05 Average 0,80 0.04 Study 2 Hof 0.80 0.00 0.80 0.20 Har 0.73 0.00 0.73 0.26-1 Mill 0.80 0.00 0.80 0.11 Bro 0.73 0.01 0 74 0.28-i Harg 0.80 0.11 0.91 0.25 McC 0.82-^ 0.02 0.84 0.17-^ Vin 0.80 0.07 0.87 0.05 Lem 0.82"* 0.06 0.88 0.16 Average 0.85 0.15 Average 0.80 0.22 Study 3 Oeh 1.41 0.17 1.58 0.35 Sch 1.41 0.18 1.59 0.25 Average 1.585 0.30 ^Consumed 1 serving of unenriched cornmeal cornbread. -Consumed 1 serving of enriched cornmeal cornbread. •^One meal eaten outside, analyzed and suitable corrections made today’s total. “^These subjects were in negative nitrogen balance. 1953, No. 1 March Thiamine Content of Diets 67 ception of the cornbread recipe, were not standardized and so offered an¬ other variable. Furthermore, not until this study had been completed was it learned that through a misunderstanding the Clemson premix used in en¬ riching the cornmeal for this study was that intended for whole cornmeal and not the degerminated meal. Consequently, the amount of thiamine added to the daily diets by the use of this enriched cornmeal in the making of cornbread was less than supposed. It is evident that the slight superio’:- ity of the enriched cornmeal cornbread diets of the present study is all that one could expect under the circumstances. However, these thiamine values suggest that in general even slight additions of thiamine in composite foods give an increase of thiamine in the daily diet. Table II gives the total daily thiamine intake (composite food thia¬ mine plus milk thiamine) and the daily urinary excretion of thiamine for 22 young college women consuming the diets containing the serving of the enriched or the unenriched cornmeal cornbread. Twelve of the 22 women were in N groups during their residence in the Home Management House and 10 in S groups. Those of group S paralleling subjects Oeh and Sch of group N, Study 3, were unable to complete the study. During Study 1, six women completed the metabolism study in both group S and in group N. The enriched cornmeal bread diet contained twice as much thiamine as the unenriched diet. The difference in the food supply (each group pur¬ chased its own foods) and in the cooking processes undoubtedly was the basis for this great difference, as the premix used in enriching the cornmeal could not produce this difference. During Study 2, the thiamine values were reversed, group S’s composite foods containing more (0.80 mg thiamine) than N’s (0.73 mg thiamine). Two subjects in the latter group had one meal outside the House, and this accounted for their higher daily intake. Although a cup of the milk analyzed during these studies furnished only 0.06 mg of thiamine, it is evident from Study 1, S-N, that the con¬ sistent use of milk materially increased the thiamine intake of the subjects. During Study 2 there were three non-milk drinkers, two in group S and one in group N. In Study 3 the milk consumed furnished enough thiamine to give these two subjects an intake which met the National Research Council’s Recommended Daily Allowance of 1.5 mg thiamine. The total thiamine intakes ranged from 0.3 8 to 1.59 with an average of 0.78 mg for the 22 young college women. This average corresponds to O. 80 found by Lane and others (1942) to be the amount consumed by the middle two- thirds or three-fourths of the population prior to the advent of enriched bread or flour. These averages are substantially lower than 1.2 and 1-8 mg reported by Stiebeling and Phipard (1939), for 25% and 75% of the population, respectively. Winters and Leslie (1943 and 1944) found the average thiamine intake for low-income women was 0.51 and for the moderate-income group 0.72 mg. With the enrichment program in progress the average for the present study is slightly higher, namely 0.78, and with the group receiving additional enriched cereal in the form of cornbread even higher, namely, 0.93 mg of thiamine. The diets consumed by the college women of the present study were representative of the moderate-income group. Even with enriched white bread and all-purpose flour, it is evident that the thiamine content of the daily diet is still dependent upon the va¬ riety of foods eaten and the way these foods have been cooked. 68 The Texas Journal of Science 1953, No. 1 March The average daily urinary thiamine on these intakes ranged from 0,03 to 0.3 5 mg. The two subjects Oeh and Sch with a composite food intake of 1.41 mg of thiamine had the highest urinary excretions, namely, 0.3 5 and 0.2 5 mg, respectively. The lowest excretions, that is, those below 0.06 mg of thiamine, occurred on composite diets of 0.3 3 and 0.69 mg- of thia¬ mine, with one exception (Vin), and that excretion of 0.0 5 was on an intake of 0.80 mg. Hathawday and Strom’s (1946) subjects excreted 0.09, 0.091, and 0.112 mg of thiamine on a natural diet containing 0.84 mg, whereas the subjects of the present study consuming a total thiamine in¬ take of 0.73 to 0.91 mg of thiamine excreted from 0.03 and 0.28 mg. How¬ ever, Hathaway and Strom’s (1946) subjects had been maintained on a synthetic diet containing 1.0 mg of thiamine for seven weeks prior to their study, whereas no synthetic diet was employed in the present study. When Oldham and coworkers’ (1946) subjects were on a freely chosen diet during their preliminary period, they excreted an average of 0.097 mg of thiamine. According to these authors, their subjects returned only 6.3% of a test dose and were therefore considered to be in only fair state of nutri¬ tion with respect to thiamine. Their subjects were examined by an experi¬ enced clinician and were found to have no deficiency symptoms. Although no clinical investigations of the subjects of the present study was possible, they expressed no symptoms of illness. However, Scoular and Foster (1946) reported an earlier study of similar college women in which they were com¬ pared with the previously reported studies of college women, and it was found that 101 Texas college women were taller and lighter in weight than those of the previous studies. In comparison with Oldham and coworkers’ (1946) group of young women, those of the present study may be con¬ sidered to be even less than fair in their state of nutrition with reference to thiamine. No doubt this poorer nutritional state is true of other nutrients also, since three of these 22 women were in negative nitrogen balance. Neither Hathaway and Strom (1946) nor Oldham and coworkers (1946) give the nitrogen balances of their subjects. Since all of the subjects of the present study either gained in weight or maintained their weight, it was assumed that the diets were calorically adequate. Consequently, it is believed that the low thiamine excretions are due directly to the low thiamine in¬ takes and that for the majority of these subjects low intakes represent a common dietary practice. The need for further studies of the thiamine intakes of college women on self-selected diets is indicated. To add to these data, a study of the thiamine intakes of college women based on their selec¬ tion of foods from a cafeteria counter is now under way. SUMMARY The daily composite food thiamine values ranged from 0.33 to 1.73 mg for group S (unenriched cornmeal bread serving) and from 0,51 to 2.26 mg for group N (receiving the enriched cornmeal bread serving) with an average of 0.92 for the former and 1.07 mg for the latter group. The cal¬ culated thiamine content of these diets ranged from 0.74 to 1,87 mg with an average of 1.18 mg. The milk consumed raised the thiamine content for all but the three non-milk drinkers. The total daily thiamine intakes ranged from 0.3 8 to 0.91 mg for the 10 subjects in S groups and from 0.73 to L59 mg for the 12 subjects in N groups. 1953, No. 1 March Thiamine Content of Diets 69 The daily urinary thiamine averaged from 0.0 5 to 0.15 mg for the S groups as compared with 0.04 to 0.30 for the N groups. Three of the subjects in Study 2 were in negative nitrogen balance, whereas all of the other subjects were in positive nitrogen balance. The low urinary thiamine excretions of 13 of these 22 subjects indi¬ cate that their thiamine reserves are low and that diets prior to this study were less than optimum. Even the slight increase in the daily thiamine content represented by one serving of a food made with an enriched cereal was observed with these diets, although the methods of cooking the other foods in the diet were not standardized. REFERENCES Association of Vitamin Chemists — 1947 — Methods of Vitamin Assay. Inter¬ science Publishers, N. Y. Connor. R. T., and G. J. StrauP — 1941 — Determination of thiamine by the thio- chrome reaction. Ind. Eng. Chem. Anal. Ed. 13: 1-8. Gyorgy, P. — 1950 — -Vitamin Methods. Academic Press, Inc., N. Y. Hathaway, M. L., and J. E. Strom — 1946 — A comparison of thiamine synthesis and excretion in human subjects in synthetic and natural diets. J. Nutri. 32: 1-8. Holt, F., and F. I. Scoular — 1948 — Iron and copper metabolism of 50 college women. /. Nutri. 35:717-723. King, Charles Glenn — 1948 — Current P^esearch in the Science of Nutrition, "Too much reliance placed upon variety of food intake.'” Nutrition Foundation Inc, N. Y. Lane, R. L., E. Johnson and R. R. Williams — 1942 — Studies of the average American diet, I. Thiamine content. J. Nutri. 23: 613-624. Oldham, H. G., M. V. Davis and L. J. Roberts — 1946 — Thiamine excretions and blood levels of young women on diets containing varying levels of the B vitamins, with some observations on niacin and pantothenic acid. J. Nutri. 32: 163-180. Scoular. F. I., and L. B. Foster — 1946 — Food intake of college women. J. Am. Diet. Ass. 22:401-403. Stiebeling, H. K., and E. F. Phipard — 1939 — Diets of families of employed wage earners and clerical workers in cities. U.S.D.A. Circ. 507, 99. Winters, J. C., and R. E. Leslie — 1943 — Diet of women of low-income groups. /. Nutri. 26: 443-458. Winters, J. C., and R. E. Leslie — 1944 — Diet in moderate-income groups. J. Nutri. 27: 185-192. TERNARY LIQUID SYSTEM: PHENOL-WATER-N-PROPYL ALCOHOL F. F. MIKUS AND S. E. CARSON Texas College of Arts and Industries The increase in the use of liquid-liquid extraction in industry has brought more attention to the study of ternary liquid systems. A consid¬ erable amount of data of physical-chemical nature is necessary for the selec¬ tion of the best method to be used and the proper design of the equipment. As there is a limited amount of such data, one must turn to the tedious experimental method for the information. Schreinemakers (1893) and Roozeboom (1894) studied the solubility behavior of ternary liquid systems in which at least one pair of liquids is only partially miscible. Both used a graphical method for representing the mutual solubility data in which the moles of component C was plotted against the number of moles of component B per moles of component C. In some cases the weight per cent of component A was plotted against the B FIG. 1 70 1963, No. 1 March Ternary Liquid System 71 weight per cent of B, In either method the amount of component C did not appear on the graph and a clear representation of the system as a whole could not be made. The method of plotting the data, most commonly used at the present time, is that introduced by Gibbs (1876). In this method an equilateral tri¬ angle (Fig. 1) is used. Use is made of the fact that the sum of the per- pendictulars Pa, Pb and Pc, drawn from any point P within the triangle to the sides of the triangle is equal to the altitude of the triangle. The length of the altitude represents 100% composition and the lengths Pa, Pb and Pc represent the percentages of A, B, and C respectively. The verticles of the triangle represent pure components A, B and C. Thus the quantities of the different components are represented as fractional parts of the whole, which is the altitude. A point on the side of the triangle represents a binary mix¬ ture of the two compounds at the ends of the side. Ternary liquid systems can be classified into various classes accordingly as the liquids are immiscible, partially miscible or completely miscible. There are three types of partially miscible systems: systems in which one, two or three pairs of components are miscible. The system reported here is of the first type. Phenol and water are partially miscible in each other, whereas n-propyl alcohol is miscible in all proportions with both phenol and water. The method used for obtaining the mutual solubility curve is similar to that described by Washburn (1932). Solutions of a pair of miscible liquids varying in composition were prepared by introducing known amounts of each liquid into a glass-stoppered flask using calibrated pipettes. These solutions were brought to 2 5 degrees C. in a constant temperature bath. TABLE I MUTUAL SOLUBILITY DATA AT 25°C. Weight Percentages D Phenol Water Propanol- 1 ^2.6° Density 71.06 28.94 00.00 1.4812 1.0480 68.78 25.39 5.83 1.4784 1.0314 65.69 23.17 11.14 1.4731 1.0176 58.57 21.10 20.33 1.4640 0.9992 52.37 20.92 26.71 1.4545 0.9760 45.54 21.83 32.63 1.4441 0.9595 41.49 22.50 36.11 1.4363 0.9516 37.15 23.93 38.92 1.4301 0.9427 29.62 27.71 42.67 1.4180 0.9313 20.76 35.06 44.17 1.4032 0.9244 15.48 43.14 41.38 1.3911 0.9261 12.65 49.19 38.16 1.3850 0.9325 10.59 53.91 35.26 1.3791 0.9382 9.44 58.00 32.56 1.3737 0.9419 8.18 61.45 30.37 1.3689 0.9467 7.16 64.49 28.35 1.3662 0.9528 4.73 72.93 22.34 1.3585 0.9622 3.41 79.06 17.53 1.3538 0.9713 3.13 85.51 11.36 1.3487 0.9816 4.37 89.58 6.05 1.3457 0.9908 8.45 91.56 00.00 1.3490 1.0033 72 The Texas Journal of Science 1953, No. 1 March The third component was added from a microburette, graduated in 0.01 ml divisions, until the appearance of a second phase was noted by a slight cloudiness or opalescence upon shaking. In order to obtain more definite endpoints, phenol was titrated into solutions of varying concentrations of n-propyl alcohol and water on the water-rich portion of the curve, and water was titrated into solutions of varying concentrations of n-propyl alcohol and phenol on the phenol-rich portion of the curve. The flasks were returned frequently to the constant temperature bath between addi¬ tions of the titrating agent in order to maintain a constant temperature. The refractive index of each of these mixtures at the endpoint was deter¬ mined with an Abbe refractometer, the lenses of which were kept at 2 5 dgrees C. by water circulated from the water bath. Five samples of each mixture were run so as to get check readings and to furnish samples for the determination of densities, which were obtained by using five ml pycnom¬ eters at 2 5 degrees C. The temperature of the bath used throughout this investigation was held at constant temperature it 0.1 degree C. by an elec¬ tronically controlled circuit. The data obtained by the above method is given in Table I. In first three columns of the table are given the data for the mutual solubility curve shown in Fig. 2. The area under the curve represents the heterogeneous re¬ gion while the area above the curve reprsents the homogeneous region. In F'lG. 2 1953, No, 1 March Ternary Liquid System 73 other words a system whose composition is represented by a point under the curve will have two phases while one represented by a point above the curve will have only one phase. It is interesting to note that the solubility of phenol in water as well as water in phenol is decreased by the addition of n-propyl alcohol until the concentration of alcohol is 12 and 15% respectively. Further additions of alcohol cause an increase in the mutual solubility until a homogeneous phase is obtained. A knowledge of densities is useful in predicting the rate at which equilibrium between the phases will be established. If the overall composition of the system is defined by a point in the heterogeneous region of the graph, two liquid phases are formed. The compositions of these phases lie on the solubility curve. A straight line con¬ necting the points representing the conjugate solutions is known as a tie line. Tie line data (Table II) was obtained by thoroughly mixing different proportions of the compounds so that the composition of the system fell under the curve and by placing the mixtures in a constant temperature bath until equilibrium was reached as evidenced by the absence of turbidity in the conjugate solutions and at the interface. This process took from a few hours to several weeks depending on the relative densities of the two layers. After equilibrium was reached the refractive indies of the conjugate layers were determined by the same method described above. The refractive indices of the conjugate layers were determined by the same method de¬ scribed above. The refractive indices of the solutions of known composition (column 4, Table I) were plotted against the concentrations of each of the components (Fig. 3). Knowing the refractive indices of the conjugate so¬ lutions and referring to F'ig. 3, their compositions can be obtained directly. The tie lines shown in Fig. 2, show that with an increase in the n-propyl alcohol, the amount of alcohol entering the phenol-rich layer is large, where¬ as the amount entering the water-rich layer is small. This displaces the plait point to the water-rich side of the curve. The plait point represents the point on the mutual solubility curve where the two conjugate phases become one. TABLE II TIE LINE DATA AT 25°C. Phenol Layer Water Layer Phenol Water Propanol-1 ^25® Phenol Water Propanol-1 n.,-o 66.8 23.6 9.7 1.4750 7.0 92.0 2.0 1.3468 56.2 20.8 23.0 1.4604 6.0 91.0 3.5 1.3460 50.0 21.1 29.0 1.4509 4.3 89.2 6.8 1.3470 39.65 22.95 37.4 1.4340 3.1 87.2 9.6 1.3475 37.6 23.7 38.6 1.4317 3.0 86.6 10.5 1.3480 29.6 27.7 42.7 1.4180 3.1 84.0 13.1 1.3501 28.6 28.4 43.1 1.4165 3.3 S3.2 13.7 1.3505 23.5 32.6 44.6 1.4080 3.5 80.0 16.6 1.3530 19.1 37.3 43.6 1.3991 3.5 77.4 19.0 1.3550 17.2 40.3 42.4 1.3953 4.0 75.0 21.0 1.3568 14.8 44.2 40.2 1.3900 4.8 72.3 22.9 1.3591 74 The Texas Journal of Science 1953, No. 1 March The tie lines, as in this case, are practically never parallel to the base of the triangle or to each other. Unless the conditions of a given problem, e.g., the application of the data to liquid-liquid extraction, are identical to those under which the tie lines were determined, it becomes necessary to interpolate between existing tie lines. Several methods of correlating tie line data, notably those of the International Critical Tables (1929), Sherwood FIG. 3 1953, No, 1 March Ternary Liquid System 75 (1937), Bachman (1940), Othmer and Tobias (1942) and Hand (1930), have been proposed. A detailed discussion of each of these methods is beyond the scope of this paper and will not be presented here. However, it might be said that each of these methods were tried on the data presented herein with satisfactory results in all cases. LITERATURE CITED Bachman, I. — 1940 — Ind. Eng. Chem., Anal, Ed., 12: 28. Gibbs, J. W. — 1876 — Trans. Conn. Acad., 3: 152. Hand, D. B.— 1930— /• Phys. Chem., 34: 1961. International Critical Tables — 1929 — McGraw-Hill Book Co., New York. Othmer, D. F., and Tobias, P. E. — 1942 — Ind. Eng. Chem., 34: 693. Roozeboom, B. — 1894 — Z. Physik Chem., 15: 984. SCHREINEMAKERS, F. A. H. — 1893 — Z. Physik Chem.., 11: 75. Sherwood— 1937— and Extraction. 5th ed., McGraw-Hill Book Co. New York. Washburn, Hnizda and Vold — 1932 — /. Am. Chem. Soc., 54: 4217. REFLECTION OF CENTIMETER RADIO WAVES FROM GROUND AND WATER SURFACES A. W. STRAITON Electrical Engineering Research Laboratory The University of Texas INTRODUCTION The Electrical Engineering Research Laboratory of The University of Texas has recently undertaken studies of the propagation of millimeter radio waves for the Office of Naval Research. As the first part of the measure¬ ment program under this contract the reflection characteristics of various surfaces are being studied. This paper describes measurements made over a 1000 foot path adja¬ cent to the laboratory building and over a 1400 foot path over Lake Austin. It is planned to use these same techniques for an overwater path of similar length along the Gulf Coast. Although the primary object of these measurements is to determine the reflection characteristic of millimeter radio waves, the measurements at lower frequencies provided an opportunity to study variations of the reflec¬ tion coefficient with frequency. FACTORS AFFECTING THE STRENGTH OF REFLECTED SIGNALS The following interdependent factors are significant in determining the strength of radio signals reflected from the ground or water: a. The angle-of-incidence on the ground b. The frequency c. The polarization d. The surface roughness and dielectric properties e. The antenna characteristics f. The path length The first three of these factors are taken as variables in the measure¬ ment described in this report. The ground roughness was not a variable, as only a single path was used for the tests of this report. The roughness of the overwater path varied with the amount of wind blowing at the time of the measurements. It is obvious that an antenna could be used with a radiation pattern narrow enough to materially reduce the illumination on the reflecting plane. This would mean, of course, that a correction would have to be applied to the apparent reflection coefficient in order to get a number which could be called the reflection coefficient of the path. Such a correction would be difficult to make without first making a number of simplifying assump¬ tions. To avoid this difficulty, the antennas used in making these measure¬ ments were chosen so that approximately even illumination was obtained over a number of Fresnel Zones of the reflecting surface. The path lengths were chosen so that grazing angles up to about 5° could be obtained with the towers abailable and so that the effect of wave curvature would be small. 76 1953, No. 1 March Reflection of Centimeter Radio Waves 77 METHOD OF MEASUREMENT The method used for obtaining the reflection coefficient was that of measuring height-gain curves. For the overland path, the transmitter and receiver were raised simultaneously to heights of 50 feet. The simultaneous and synchronous movements of the transmitter and receiver were chosen in order to keep the center of reflection at the same point. For the over¬ water path, only the receiver was raised, as there was little significance m keeping the point of reflection constant. FIG. 1. Transmitting Tower. 78 The Texas Journal of Science 1953, No. 1 March From these data, curves were drawn through the maxima and minima of the interference patterns. The reflection coefficient at a given height was taken as the quotient of the difference and the sum of the maxima and minima curves at that height. A picture of the transmitting tower is shown in Figure 1. The general ground coverage is shown in this figure. Some short, dead, grass stalks were standing and a sparse matting of grass stalks was on the ground. Degrees Fig 2. - Antenna Patterns In Vertical Plane 1953, No. 1 March Reflection of Centimeter Radio Waves 79 FIG. 3- Antennas. ANTENNA CHARACTERISTICS The antennas used in the measurements were as follows: Wave Length CM Polarization Angle Between Halfpower Points Antenna Type 26.5 Horizontal 14.4° 40” Parabolic Reflector 26.5 Horizontal 21.0° 40” Parabolic Reflector 9.0 Horizontal o OO 18” Parabolic Reflector 9.0 Horizontal 15.2° 18” Parabolic Reflector 3.2 Vertical 15.8° 4” X 4” Horn 3.2 Vertical 18.6° 4” X 4” Horn .86 Vertical 14.8° 1” Circular Horn .86 Vertical 20.0° 1” Circular Horn The radiation patterns for these antennas are shown in Figure 2. A picture of the antennas is shown in Figure 3. Identical antennas were used at the two ends for each measurement. A number of other antennas with narrower beams were also tested, but these tests contributed little additional information to that found with the antennas listed above. 80 The Texas Journal of Science 1953, No. 1 March ORIGINAL DATA A sample of the original data for each frequency is shown in Figure 4 for overland transmission. No difficulty was experienced in plotting the envelope of the maxima and minima signals for the 26.5 cm wave length. The envelope of maxima and minima for this case became somewhat irregular for the 3.2 centimeter measurements and was very irregular for the 8.6 millimeter measurements. The reflection coefficient was calculated RECEIVER HEIGHT ABOVE GROUND — FEET FIG. 4 - SAMPLES OF ORIGINAL DATA Reflection Coefficient - K Reflection Coefficient 1953, No. 1 March Reflection of Centimeter Radio Waves 81 — Theoretical Curve For Fig 5.- Reflection Coefficient Curves For Horizontal Polarization Fig. 6.- Smoothed Reflection Coefficient Curves For Horizontal Polarization Over (and Reflection Coefficient 82 The Texas Journal of Science 1953, No, 1 March Fig. 7 Smoothed Reflection Coefficient Curves For Vertical Polarization Overland Reflection Coefficient For Horizontal Polarization Fig. 8. 1953, No. 1 March Reflection of Centimeter Radio Waves 83 from the envelope in each case, giving the irregular curves shown in Figure 5. A smooth curve was drawn through each of these curves and was used for the comparisons of the next section. COMPARISON OF REFLECTION COEFFICIENT CURVES Overland. A set of reflection coefficient curves using the antennas de¬ scribed in the preceding paragraph and radiating a horizontally polarized signal is shown in Figure 6. A set for the same antennas with vertical polari¬ zation is shown in Figure 7. The reflection coefficient curve for an infinite smooth plane with a dielectric constant of 4 is shown in each case for com¬ parison. This curve is approximately the same for all frequencies used. From these curves, it is evident that the reflection coefficient decreases appreciably as the frequency is increased, becoming very small for 8.6 millimeters. The three lowest frequency curves apparently approach unity as the grazing angle approaches zero. It is difficult to extrapolate the re¬ flection coefficient curves for the 8.6 millimeter waves to zero grazing angle as the reflection coefficient is changing rapidly in this region. The reflection coefficient for vertical polarization is in general less than that for horizontal polarization. Overwater. The overwater tests were made on four days during which the wind varied in speed from 4 to 20 miles per hour. The 10 centimeter measurements were made on the roughest day during which the waves on the lake were approximately 6 inches in amplitude. The reflection charac¬ teristic were those of specular reflection with reflection coefficients near the theoretical values. The three centimeter measurements made on the two roughest days also showed characteristics of specular reflection. Reflection Coefficient For Vertical Polarization Fig. 9. 84 The Texas Journal of Science 1953, No. 1 March The 8.6 millimeter signal showed specular reflection on the smoothest day but showed characteristics of diffuse reflection increasing with rough¬ ness. The time variations on the roughest day were approximately 10 db and considerable averaging had to be done to obtain the reflection coeffici¬ ent curves. The curve for reflection coefficients for horizontal polarization are shown in Figure 8 and for vertical polarization in Figure 9. The measured curves are compared with theoretical curves calculated for a dielectric con¬ stant of 8 1. CONCLUSIONS Overland. The reflection coefficient for 8.6 millimeters for the field test did not exceed 0.4 and dropped to less than 0.1 at angles of grazing above 2.5 degrees. The reflection coefficient increased with wave length and approached the theoretical curve at a wave length of 26.5 cm. The envelopes of maxima and minima of the height-gain curves and the resulting reflection coefficient curves were very regular for 26.5 and 9.0 cm wave lengths, but became somewhat irregular at 3.2 cm and were very irregular at 8.6 millimeters. Thus it would appear, for the path used, that the surface was smooth at 26.5 cm and rough at 8.6 millimeters. Overwater. The 10 and 3.2 centimeter waves showed specular reflection characteristics even for the roughest water conditions. The 8.6 millimeter waves showed specular reflection characteristics for the calm day but were effected by the roughness caused by even small winds. THE ADSORPTION OF SURFACE-ACTIVE REAGENTS DURING FLOW THROUGH POROUS MEDIA TURGUT Y. GULEZ AND HARRY H. POWER The University of Texas During the past two decades great progress has been made in the de¬ velopment of techniques for improving the efficiency of oil recovery. U] Qf great importance is the well-established system of flooding in which water is injected under pressure into oil-bearing formations by means of injection wells, generally ringed around a production well. These formations are fine¬ grained, tightly packed sands, which contain residual oil remaining after the primary phase of production has been completed. The mechanics of the flood involve the formation of an oil bank ahead of the advancing water and its removal through a producing well, which results in a reduction of the oil saturation to values ranging from twenty to thirty percent of the total pore volume for the most favorable primary and secondary recovery mechanisms. It would seem obvious that some form of chemical treatment that will affect the displacement of oil from porous rocks in connection with conventional fluid injection operations should prove to be attractive for the profitable recovery of increased quantities of oil. It has been known for some time that certain cationic and non-ionic chemicals, particularly those possessing the property of reducing the surface tension of water at low concentrations, will increase the recovery of oil in water flooding operations. These compounds are referred to frequently as ^'surface active” because of their behavior at a liquid surface. When they are mixed with water, their molecules exhibit the unique tendency of collecting at the contact between the liquid and a solid or between the liquid and a gas. Thus, when the normal surface of water molecules is replaced by totally different groups of atoms, a radical change is effected in the physical relation between the water and other substances with which it may be in contact. D] Although surface active chemicals have been effective in the artificial control of the interfacial tension between water and oil, they have so far failed economically in practical applications for the reason that the more effective the compound the greater the tendency for it to be adsorbed on the solid surfaces. The advancing water front becomes depleted of these reagents before any beneficial effects can be realized, and the cost of the chemical required is entirely out of proportion to the value of the additional oil recovered. Chemicals which are not so adsorbed on the sand surfaces may not suffer a loss in concentration as they are carried by the reservoir fluids, either water, oil, or both, from the injection well outwards in the direction of the producing wells. This latter class of surface-active chemi¬ cals is of particular interest in the current experiments which have been designed to determine their loss in concentration, if any, with increased con¬ tact as they flow in porous media to meet fresh sand surfaces. A brief description of the various surface-active chemicals and their properties will afford a better understanding of their effectiveness in the 85 86 The Texas Journal of Science 1953, No. 1 March FIG. 2 FIG. 3 1953, No. 1 March Adsorption of Surface-active Reagents 87 reduction of surface and interfacial tensions and hence the recovery of addi¬ tional quantities of oil from porous media. SURFACE-ACTIVE REAGENTS Certain solutes in low concentrations have the property of lowering the surface energy of their solvents to a marked degree and have been classi¬ fied as surface active reagents. Soap is one of the best known and oldest of these materials. Surface activity has been studied most extensively in aque¬ ous systems. However, it can also be demonstrated in non-aqueous solutions. For example, oleic acid is distinctly surface active when dissolved in hydro¬ carbon oils. Many other oil-soluble substances not soluble in water are known. Surface active agents may be classified on the basis of the uses to which they are selected, on the basis of physical properties such as solubil¬ ity in water or oil, and on the basis of chemical structure. With reference to chemical structure, the surface active reagents have been arranged for the most part according to the manners in which the hydrophilic and hydrophobic groups are joined, that is, directly or indirectly. If they are joined indirectly, the nature of the linkage is also of importance. Many surface active reagents have a characteristic linear molecular structure, somewhat longer than wide. The radicals which compose one end of the linear structure are compatible with the solvent, whereas the radicals which compose the opposiite end are incompatible with the solvent system. A hydrocarbon radical of hydrophobic nature which is character¬ ized by weak residual valence forces usually comprises one end, while the other end of hydrophilic nature is provided with strong residual or second¬ ary valence forces. Surface active reagents so characterized are of pri¬ mary concern in the experimental work described herein. Chemically, two principal classes of surface active agents are of inter¬ est. A class of increasing importance, the non-ionic, has non-ionizable end groups of high affinity, which usually include oxygen, nitrogen, or sulfur atoms. Although this class is important primarily in non-aqueous systems, a number of them have been used successfully in aqueous systems as emul¬ sifiers and also as straight detergents. There are two main divisions of the ionogenic class of surface active agents. The mblecule is known as anion active or simply anionic if the elongated portion with low affinity is included in the anion in aqueous solution. A typical anionic surface active agent is sodium stearate, which ionizes in the solution to form Na+ and the long chain stearate anion, CitHssCOO", which is considered to be responsible for the surface activity. Cetylpyridinium chloride is an example of a cation or cationic surface active agent which forms a cation containing the elongated low-affinity portion of the molecule. Other examples of cationic surface active reagents are the water soluble salts of fatty amines, and high molecular weight quaternary ammonium salts. Cationic compounds retain their surface activity when other cationic or non-ionic surface active agents are present. However, their activity is impaired by anion-active agents or certain inorganic anions with which combination takes place to form compounds of lower water solubility. 88 The Texas Journal of Science 1953, No, 1 March 1953, No. 1 March Adsorption of Surface-active Reagents ^9 22 a 30.5 38a 4ea sso % ea na 22.5 30,5 saa 46a 530 DISTANCE FROM INLET , INCHES DISTANCE FROM INLET , INCHES 90 The Texas Journal of Science 1953, No. 1 March Table 1 PROPERTIES OF SURFACE ACTIVE CHEMICALS NO. TRADE NAME CHEMICAL NAME CHEMICAL MOLECULAR FORMULA WEIGHT Solubility Hydrocarbons Water Non-Ionics 1 Ethomeen S/25 Tertiary soya amine (reacted with 15 moles ethylene oxide) /(Cl^CH^O^H R-N '^(CH2CH20^H 934 No Yes Z Ethomid HT/60 N-substituted hydro¬ genated tallow amide (reacted with 50 moles ethylene oxide) H /(CI^CH20)^H R-C-N '^(CH2CH20:^H 2476 No Yes 3 Ethomid HT/15 N-substituted hydro genated tallow amide (reacted with 5 moles ethylene oxide) R-C-N ''(CHzCH^kH 496 Slight Sparingly 4 Ethotat 242-60 Tall, Oil tatty acid (reacted with 50 moles ethylene oxide) R-C-0-(CH2f.H20)j^H 2448 No Yes Cationic s 5 Armac SD Soya amine acetate RNH2 RCOOH 334 Yes Yes 6 Arguad S Soya trimethyl ammonium chloride cjq R - N CH3CI 346 No Yes CHj 7 Arguad 2C Dicoco -dimethyl ammonium chloride 448 Yes Up to 100 ppm R CH3CI Non-ionic surface active reagents do not ionize. They are water sol¬ uble to unionized polar groups such as hydroxyl and other linkages, and have the advantage of being compatible with cationics, anionics, other non¬ ionics and with most of the inorganic ions. CHEMISTRY OF SURFACE ACTIVE REAGENTS USED IN INVESTIGATION The various surface active chemicals used in these experiments arc products of the Armour Chemical Division and will be described "Arquads” is the trade-name given to a series of quaternaries, members of which vary in length and number of long-chain alkyl groups attached to the nitrogen atom (Table IV). The following general formulae are characteristic of the series: [' CH3 1 + — r CH3 1 -b R-N - CH3 Cl or R-N - CH3 1 Cl 1 . CH3 1 R Alkyl Trimethyl Ammonium Dialkyl Dimethyl Ammonium Chloride Chloride The "R” group represents a long chain hydrocarbon derivative of a fatty acid. The alkyl quaternaries are water dispersible, while the dialkyl quateraries are soluble in most hydrcarbons and other organic solvents. All compounds >. .G TS „ CN rn rO X rn q X X X X X rn X X S'gS ,_. q q q q d q q q q q q q q cS.? . Y— . erme to L md 0) ^ U ^ ,.1 ON ON On On ON ON ON ON ON ON On On ON ON OJ r^ r^ r- P' r- I'- T' r- n- r^ to Pressu: Drop (Pl-P.5 Psig X X X X X X X X NT X X q X % 3 c bi 1 r-l T-. r-. 1 r—l 1—1 r— i r—l r-. 6 <2 ^3 O *5 C\ ON ON ON ON ON ON ON ON ON ON <0N ON u d X Nt X q X q q q q q q rC-. oc q o - ® O O PL mOh ^ d d d d d d d d d d d d d d \r\ § i^ 1^ n~ n- p'' r-' 00 ' . u ■43 Sii ^ ON q q q q q q q q q q q • u OJ CO ^ 3 a ^ c * 0 fH '-' Cl WPh ^ C m ION l/N ITN i/N ON ITN m ITN 1/3 m ION m m >00 2 .G _o OJ 00 00 CO 00 CM (N CN (N m 00 (N fN 0 'G '2 ft ir\ 0 0 0 0 NO fN CN fN fN CN 0 f3.| fN y '2 ^ 0 r- I^ 1'^ r^ r- t'- r'- ^ ^ .. ■a ' ^7<;s .2 c d d d d d d d d d d d d d d "S K •• § ^ r: 1 ^ So2 q q 0 0 q q q q q q q q q 0 Q 0 0 1/3 \6 On ON m q 06 CO ITN m m 1/3 d On r s MN rn 'G' q q NT q q q q q rfN 0.^0 0 rCi rn rn m m rn m rn m q rn m rr, rn i ^-2-^ ^ ^ rT^ vZ? ^ . ^ ftf^.^ C c 0 0 'O r\i r-H .-H 0 r-. C C q 0 1-^ q q q q q q q q q q 1— 1 ON f3| o id id id q q q q q q ITS q. q q q ■''4? ^ ^ ^ S; S 'S ^ :3 ^ \o C NO NO 0 NO NO NO NO q NO NO cq C< CieJ § ik 3 q q q q 0 n- cc q ni q q q q 0|0Z oi d d ni d d r-' d ri d d .d GJ cO 'O 0 NO NO NO On r- 00 NO NO q 0 n (U M w e Mh cTi rPi r S i y q q 0 0 0 q q q q q q 0 q q -2 0 a 0 0 G 3 rd d NO NO ni q q q i-n q q q P^ 1^ ° fTi rOi m m m m on m rn m m m m m on 35. *2 r« '3 ^ G 'S -t-> 0 U3 0 0 0 0 0 0 0 0 0 0 0 0 OJ tu '2 tS m fN q CN (N r— 1 00 t— . >— 1 I—. T— 1 q ^ u P f G a 2 a S d r 'd a o B 6 0 I5S t3 y S 0 On 0 On q q q q 0 d 0 d q r-- q d q q 0 d q q q q 0 d q q ® y be r— ( CM r.1 CN m m m (N I— 1 CNl ni (N m ni ^ 2 00 CO 00 00 CO CO 03 00 0 00 00 00 00 00 OJ ^ 1—1 > ^ (/j nSi ^ (/3 . . CO O -C y 5 be ts 5 S P^ ^ m m m m m rn m m m m m m rn m 'o '>i ^ S .. 8 .. rn d“ (j CG ^ 0) 73 ft "y § • ^ ^ CO S 'S o5 ^ q 06 q 06 q q q q 0 d 0 d q d 0 d q q 0 d q q 0 d q q q m r^ 00 00 00 On On ON 00 r- 00 00 On c\ 00 ^Psll .. o 1 S § -NT q q q q q q q q q q ■3 ^ •■§ m rTi rTi m m m m m m m m m m m g a ^ •s ^ «4o <3 oncen- tration ppm. 0 0 0 0 0 0 0 100 0 0 0 0 100 0 100 0 100 V S' 's *44 “TS $4 K ~pj 'tS! •CX §; S4 g 8 0 0 c^o oS d Cr 03 G ' S' d ' cr i-i 03 d ' cr u ' a 1.^ D a ’6 03 "o -G a 0 -G a 0 s a 0 •a a 0 -5 a 0 -G Q < < C < d < W w W w w w W Ethomeen S-25 10 3479-0 3822.0 40.50 34.0 0.018 7.26 2.06 5.20 344.0 0.7371 1.9" 0.491 1.479 11-7 92 The Texas Journal of Science 1953, No. 1 March 1953, No. 1 March Adsorption of Surface-active Reagents 93 are compatible with anionic materials such as soaps or other common anionic surface active agents. They are stable at both high and low pH values and also stable in the presence of most water-soluble salts. The so-called "Ethomeens” vary in cationic tendency from strong to almost non-ionic type and are stable to hydrolysis in all concentrations of acids and bases. They are tertiary amines where one fatty alkyl group and two polyoxyethylene groups are substituted on the nitrogen. The non-ionic "Ethomids” are fatty acid amides with polyoxyethylene groups substituted on the nitrogen atom. They are neutral chemically and rather unreactive. The "Ethofats”, non-ionic, are mono-fatty or resin-acid esters of poly¬ ethylene glycols. Table 1 shows the principal characterizing features of the surface active chemicals used in this investigation. EXPERIMENTAL APPARATUS In order to study the effect of surface active chemicals on sand surfaces as they flow through porous media, apparatus was designed as shown in Figure 1. The experimental flow system consists of a 1- Vs -inch inside diameter Incite tube, ^Yz feet long, and provided with screw caps on both ends. The tube is divided into six sections, the two end sections each 6^ inches long and the four internal sections each 8 inches long. Two manometers are connected on the end sections in order to determine the pressure drop through the sand column. A Incite tube 8 feet long and 1-%-inches inside diameter is used as a constant pressure displacement reservoir whereby nitrogen pressure is exerted from above to displace the aqueous solution of the various chemicals. The rate of flow is regulated with a needle valve installed on the outlet of the tube. A vacuum pump connected to the top of the tube serves to suck the solution from the containing bottle into the displacement reservoir to the desired level. A wet test meter is placed at the outlet of the sand packed tube to measure the rate of flow of gas through the sand column in the determina¬ tion of its overall permeability. The exit line from the sand packed tube is connected to a graduated separator and from there joined to a back pressure control tank equipped with pressure guage and control valve for venting the gas (nitrogen). Various views of the apparatus are shown in Figures 2 and 3. PROCEDURE A four and one-half foot Incite tube was packed with clean Ottawa sand which had the following typical chemical analysis and size distribution: See Chemical Analysis, page 94. In order that repeated tests could be made utilizing sand columns of similar porosity and permeability, a procedure for packing the column was outlined and followed. It was found that a minimum porosity of 40 per cent could be obtained, and that no decrease in porosity was possible by filling the column at rates less than one inch per minute with horizontal vibration. After the sand column was packed, the chemical solution of desired initial concentration was prepared and brought up to the desired level in the constant pressure displacement reservoir by use of a vacuum pump. 94 The Texas Journal of Science 1963, No. 1 March Chemical Analysis (12) Silicon dioxide (Si02) 99.65 % Iron oxide (Fe203) 0.022 Aluminum oxide (ADOy) Titanium dioxide (TiO“) 0.19 0.017 Calcium oxide (CaO) 0.02 Magnesium oride (MgO) trace Loss on ignition 0.04 99.939% Size Distribution U. S. Standard Sieve Size Weight Per Cent 35 78.7 45 19.62 60 1.42 100 0.26 100.00 Nitrogen under pressure was flowed through pyrogallol and 66 Baume Sulphuric acid for purification and then introduced at the bottom of the column and the sand therein flushed with ten pore volumes through the separator and the gas control chamber. The permeability of the column was calculated from data obtained by flowing nitrogen through the column, the rate of flow being determined with a wet test meter connected to the outlet of the tube. The pressure drop through the sand column was deter¬ mined with two manometers connected to the inlet and outlet respectively. The chemical solution of known initial concentration was displaced at a constant rate in the sand packed tube by exerting pressure on top of it and regulating the needle valve on the bottom of the displacement pump. A flowrator was connected to the flow line between the constant displace¬ ment pump and the sand packed column to maintain a constant rate of solution flow. The permeabilities to gas and for each chemical solution are shown in Table II. No material differences are noticed in the permeabilities to distilled water and the various chemical solutions. When the solution-nitrogen interface was moved to a position opposite the first port, a sample of the solution was removed and the surface tension determined by the Du Nuoy tensiometer, and the concentration interpolated from Figure 18. The above procedure was repeated when the solution-nitrogen interface reached the second port and for all subsequent port positions in their pro¬ gressive order up the column. Data was obtained for concentrations of 100 ppm of the following compounds: A. Non-ionics 1. Ethomeen S/2 5 2. Ethomid HT/60 3. Ethomid HT/ 1 5 4. Ethofat 242-60 B. Cationics 1 . Armac SD 2. Arquad S 3. Arquad 2C 1953, No. 1 March Adsorption of Surface-active Reagents 95 ~i — r — T" ? s * i i 1 g t S ssiy I r "it? ‘ I i:f.i m w 1 S E g IB o o 1 1 1 Bgur* 17 SURFACE TENSION VS TIME 1 1^ ll 1 o wa/SlNACI ‘NOISNll lOViUnS •wV83NAa ‘NOISNSl. TIME. MINUTES CONCENTRATION IN PARTS PER 96 1953, No. 1 March The Texas Journal of Science c _o c s o o O o O O I'l h CN 1/^ ITS VO q q m irv NT irv i % G\ d d ON rn (N d vd vd d o o c >> 'O lOV p" VO 1'^ VO VO vrv VO VO c Cl VH u p Q s CO 00 u o m o o ON >rv irv q VO q I— ( q ir\ q irv 00 d ITN d Cv d (N d vd vd irv _o CN vO VO ir\ r- VO VO VO \r\ VO VO •-5 CM q Nf- l/V VO q q q q irv q Vi &C lO Gs VO d vd Cv d fN d 00 vd 00 c VD VO VO r-v VO r- VO VO vrv VO irv •-I G3 00 .s a g S -S; ‘.Jv ai \ q q 5— ( q 00 q q q (N q q m % 00 fN (d vd d fN fN d d d d '2 c >, VO VO VO r-. r". VO VO VO VO irv tv tv _o Q o o N-., in C 2 rvj rr\ 00 _i li'V q O q fN >rv q o H £ e? > r- Nf NT NT NT irv NT Nf u D P CO c s .0 u in c 0) (0 .s $ CN [S o q q q q 00 I— 1 NT q o 01 p d d d d d fN 00 00 00 fN vd « cfl O C NT NT NT NT NT NT N' (TV Nl' NJ- g 0 w u 0 ° .2 Vi e 0 s _> tj s ^ o ^ a Roorr 2 0; a o 0 q (d o VO q vd O vd O vd q (N q d q d q d c d q d S ‘3 S o 2 g S u fTi rC\ CC) rT) (TV rC\ rfV rC) m m OJ rv qj ^ Ch yjO * d c in gV/DVO .2 M-( 0 a "2 cq £ a o o o o o O O O o o CJ • —1 . 00 s ^ — 1 rH r-H r—i OJ o vts '-5 o C OJ -C H tV!, S '55 ^ 5s G 2 ® ^ §o-p o O 'g i-> a u U 0 Q O q fN NT o q (N NT irv H K irv H X 'i) CN fN C/D OO CO CO fN I P < D a < < •TJ ■ p 00 o o m r- ^ ^ ^ ^ ^ ^ ^ o\ w 00 o ^ Xf v~l ^ o w XT' c/3 « OJ P.1 ^ ^ ^ f-* .2'^ 1"" fN t_J O O iTN ITS O »-H ' rn '> P o ^ qj O Oi X ^■ § § OPPhEOOO s s a ^ OJ I s •S 0 u ^ < z OJ Oi 6 H 6 o o 1953, No. 1 March 98 The Texas Journal of Science _c 6 ir\ -o c oo \o CO "1 o "G (N (U rG VD 00 105 r-- G o 05 d r-H rOi ON d q CO CiJ CO \r\ 'O m 105 ION tH W 'G 05 S u -G G G CO x; G rr\ q (05 G o q (U G 03 Oi CO rn CO C q NO f'’ ITN yrs G p' G >05 0 - 'P- 05 qj u 't^ -G G G G CO X G VD lOs ON q q q CO CM CO NO (ON 1^ 04 iO\ lr^ (05 G (05 >05 g; G X 05 03 G G ON G 105 q (N q CO G d On q d 04 CO d ^r^ VG rOi 105 G >05 o c G g "O q q \05 NO >05 03 r4 CO G d d d CO ION 105 (05 G >05 >05 G G 6 o .2 o. o o C O o o C/ n. o 1 — 1 O o o G o3 O i-( G U o o o NO vp q H rt _o G G (N (N CN G (>) U rN U PM Q X 's 05 CO G G X D 03 M-j G « G C3 a U 'o X o X G G Ui G O a o X W W < < < < TABLE VI CHEMICAL LOSS AT SAMPLING POINTS 99 1953, No. 1 Adsorption of Surface-active Reagents ^ March a o OJ .S 3 'X3 ^ TO tj' \o « o s -s "I i4 M ^ I s ft ® p«] o' ^ O « •s M ^ > g d C ^ g fi eS ^ ^ m y o -S u ^ s 1 a O < 2 o o e o « bj O 42 o H H ^ > cs g m i.i 1 s g m I ^ o d bo ■© S Ph cor'COO'^O'^ om'Oma\(»cNr'- QfNjG\\0'^ mencM o^’odddoo ovoor-M\ooo\o OON<^^_ irsvqvo >o ' A ITS ^ .2 =3 S M ^ r- O i ^ C rsi ir\ »rN OOOOOCOO oocooooo ofN'vf'\0MOCN'--r o >—1 fN rCi vr VO r- oc oo'^rN^xri^O f— I I I-H CM O O O O O ir\r^r^^C\ONr^ Orn^CN^fftOVO doHdrsirnN^d O ir^ 0\- ro dddddddirs ON CN o 'T I I—H fNl rr- rT: O O O O O o 0«/N>/N>/Nirsi/N»r\»/N OOOrnmfnmrCNfNN oopppppp dddddddo trxOOOOOOO rniTNOOOOOO ^ooooooo op^pppppp dd'ddcddo u-vooooppp dddddddo fr\ VO ^ O .s? rE © s o p •V ^ m 'O 'O 'O © © S % ■ft 'ft > > 0) © HH 100 The Texas Journal of Science 1953, No. 1 March The results obtained for water alone and also for each chemical were plotted as surface tension versus distance from inlet of the sand column as shown in Table III and in Figure 8 and succeeding figures. Referring to Figure 18, it will be seen that surface tension is an inverse function of con¬ centration. This inverse relationship must be kept in mind in the interpreta¬ tion of Figure 8 and succeeding graphs. Figures 16 and 17 show the effect of time on surface tension of a typical cationic and a typical non-ionic chemical solution. See also Tables V and VI. These experiments show that the effect of non-ionic surface active com¬ pounds should be distinguished clearly from the generally unsatisfactory experience which has resulted from the use of cationic compounds which tend to become adsorbed quickly on the sand surfaces. The non-ionic com¬ pounds have maintained their surface active properties after long periods of contact with sand. It has been shown that Ethomid HT-60 at a concentration of 100 ppm and 10 ppm in contact with a sand column 4^2 feet long lost comparatively little by adsorption. Other surface-active agents were lost quite rapidly by adsorption onto the sand surface. The performance for Ethomid HT-60 has been confirmed by a California producing company recently by means of flooding tests on large cores. They were able to reduce the oil content of the core to a residual saturation of 10 per cent by flooding with a 10 ppm concentration of this chemical in water solution, Fro mthe data plotted it is seen that some surface tension readings increased to a maximum after which lower values were attained. This phe¬ nomenon can possibly be explained by the by-passing of the solution in the hand-packed sand column. 1953, No. 1 March Adsorption of Surface-active Reagents 101 Artificial control of interfacial tension between water and oil by the use of surface tension depressants has, so far, failed in practical application because the more effective the surface active compound, the greater is the tendency for it to be adsorbed on the solid surface. The advancing water front, therefore, is depleted of these reagents before any beneficial effects can be realized. Of new interest, however, is the group which does not have the ten¬ dency to become adsorbed on the sand surfaces. Further research may reveal that this group may become of great importance, economically, in the increase of recovery of petroleum from reservoirs beyond the yields normally expected from primary and secondary recovery operations. ACKNOWLEDGEMENT The authors wish to acknowledge their appreciation to Mr. Paul D. Torrey, Manager, Oil Recovery Chemicals, Austin, Texas, and to the Armour Chemical Division, Chicago, Illinois, for making available the means pro¬ vided for this research program. Appreciation is also extended to Dr. J. H. Prusick, Armour Chemical Division, for his assistance and help in the chemi¬ cal differentiation of the various surface active compounds used in this investigation. BIBLIOGRAPHY ]. Grfgopy P. G., C. R. Groniger and T. H. Prtistgk — ''Chemical Treatment Flood Waters Used in Secondary Oil Recovery.” Paper presented at the 117th meeting of the American Chemical Society, Houston, Texas, March 27, 1950. 2. Breston, J. N. — 1949 — New Chemical Treatment of Flood Water for Bacteria and Corrosion Control. Producers Monthly, May 1949. 3. Torrey, P. Z. D. — New and Suggested Techniques for Improving the Recovery of Oil,” Second Petroleum Recovery Conference. Paper presented at the A. & M. College of Texas, April 19, 1951. 4. Breston, J. M., and J. K. Barton — 194'7 — Fie'd Test of Corrosion Inhibitor for Low pH Waters. Producers Monthly, November 1947. 5. Heck, E. T.. J. K. Barton and W. E. Howell — ''Further Field Test Results on Use of Corrosion Inhibitors for Secondary Flood Waters.” Paper presented at the Pittsburgh, Pa., meeting of the American Petroleum Institute. 6. Mann, C. A., B. E. Lauer, and C. T. Hultin — 1936 — Organic Inhibitors of Corrosion — Alipathatic Amines. Ind. Eng. Chem. 28; 159-163. 7. Schwartz, A. M., and J. W. Perry — 1949 — Surface Active Agents. Inter-science Publishers, Inc., New York 8. Young, C. B. F., and K. W. Coons — 1945 — Surface Active Agents. Chemical Publishing Co., New York. 9. Plating and Finishing Guidebook. New York Metal Industry Publishing Co., Inc. New York. 10. Ethomeens, Ethomids, Ethofats. Bulletin furnished by Armour Chemical Company. 11. Arquads. Bulletin furnished by Armour Chemical Company. 12. Chemical Composition of Ottawa Sand, Personal communication, Aug. 13, 1951. 13. Perry, J. H. — 1941 — Chemical Engineering Handbook. McGraw-Hill, New York. 14. Calhoun, /. C., McCarty and Morse — 1950 — Effects of Permeability on Secon¬ dary Recovery of Oil. Secondary Recovery of Oils in the United States. 15. Prusick, J. H. — -1951 — Secondary Oil Recovery. Oil and Gas Journal, Aug. 9, 1951. 16. Prusick, J. H. — Personal communication. BOUNDARY CONDITIONS IN THE FOURIER INTEGRAL FORMULATION W. F. HELWIG The University of Texas In the theoretical analysis of electrical and mechanical systems, the first step confronting the investigator is the formulation of a mathematical expression relating the interaction of the various elements under the appli¬ cation of imposed forces. Fortunately, due to the discoveries of Messrs. Newton and Kirchhoff, a set of rules is available which, for simple systems at least, outlines methods of procedure that are relatively easy to apply and result in reasonably accurate expressions in the form of differential equations. The next step, which is the solution of the differential equation, is not quite so simple and requires not only a knowledge of this branch of mathe¬ matics, but in addition calls for an understanding of the physical reactions of circuit elements at the outset of the analysis. These are called "initial condi¬ tions” of the problems and frequently are the most troublesome details involved. In fact, under some circumstances, the initial conditions cannot be arrived at from elementary principles. Toward the end of the last century, Oliver Heaviside of England pro¬ posed for circuit problems a method of solution in which initial conditions were automatically accounted for by formulating the problem on the basis of zero energy conditions at time t equals zero. By this means he was able to solve many practical problems which had previously defied solution. His method was really an extension of the old D operator of linear differential equations so modified as to eliminate the necessity of evaluating the constant coefficients in the final solution. Employing this method purely as a means to an end, he was not interested in mathematical rigor and consequently gave no formal proofs for his formulation. For many years his "experi¬ mental methods” were regarded with some contempt by the pure mathe¬ maticians of his time and were ignored. The practical success of his methods, however, finally focussed attention on his work, and mathematicians became interested in its application. Many of his developments were placed on a much sounder footing and a fairly workable set of rules was devised. This operational method, although in many ways more convenient than the classical methods of differential equations, had nevertheless at least two serious drawbacks: the limitation on the initial energy conditions and the absence of a direct method for getting the opera¬ tional forms. In spite of these objections, however, the usefulness of this type of approach became evident and an operational method based upon more rigorous principles was in high demand. The methods of Fourier were found to satisfy these requirements and are peculiarly adapted to the analysis of oscillating systems. Briefly, the method requires that an operational function be found in which the driving force is expressed in terms of a frequency spectrum. Each increment of frequency is then applied to the system impedance, which 102 1953, No. 1 March Fourier Integral Formulation 103 is expressed in simple alternating-current terms. The components of system response are then combined by means of an infinite bilateral integral, giving the complete required solution of the problem. Theoretically, the scheme appears to have all the requirements for a useful operational method, but practically some difficulties arise. The pro¬ cedure outlined above makes no provision for initial energy conditions, and the integration of the operational transform along the entire real axis presents a formidable task. The latter troublesome feature is overcome to a great extent by resorting to a table of transforms, now available, which intreprets many operational forms. Theorems on the combining of transforms take care of other cases which may arise. The handling of initial (boundary) conditions is the subject of this paper, which will endeavor to show how the superposition theorem may be employed in this connection. If the Fourier unilateral integral is provided with a convergence factor, the operator becomes complex and the direct transform is represented by the Laplace integral as shown below. 3’(oj)^Lim (i) As an example, let us consider a simple R-L-C circuit, as in Figure 1 : Fig.l Here we have all three of the alternating-current impedance elements repre¬ sented and the circuit is assumed to have both an initial current flowing and a charge on the capacitor. The Kirchhoff equation of potential drops is = V(t) (2) An approach will be made through the use of the Laplace transform. Employing the Laplace method, we solve for the required transforms F(5)=’ j.crvJ d-l) d.n) O from which we get « sr(s)-f(0) 0.2} O Similarly, a different integration by parts gives F'cs) C * dt c 1 . 1 2 ] from which 104 The Texas Journal of Science 1953, No. 1 March Applying these conversions to our example^ «r (zi) - \/(s) C2.i;i so JC^) VCs} -I- ^ LL (2.5) ^ Ls * */^5 The above transform suggests that the final current is composed of three separate components: one due to the impressed driving force, one due to the initial capacitor voltage and one due to the existing current. Employing the limiting form of the integral where oc cj, the method is directly applicable to the Fourier transformation, and the existent initial conditions may be handled as additional sources. A mechanical analogy may serve to illustrate the method more clearly. The corresponding mechanical system is shown below in Figure 2. Ffrj K n tp K is the spring constant Rni is mechanical resistance M is mass 2 Here n ii- W ^ Rx - Fct) (3) which may be written, where Wt diJ’ f n w ^ R^v K jvdt = ha) (3./) If we suppose the mass has an initial velocity Vq then the kinetic energy available due to the moving mass at time t — o, is Differentiating, we obtain = tiv M If we call this a driving force Fj, then in general {¥.!) So Mvq may be regarded as an impulse. From equation 1.13, the initial spring deflection is represented by the transform J" /a)df which here becomes The analysis of complex networks of several meshes may then be written from elementary alternating-current theory as Mt, + + and so forth. Ea £/") + L, L, - E, ce-) (5J) 1953, No. 1 March Fourier Integral Formulation 105 We would get for a third-order system E. E, lAZl 1^21 1 2,. 2^.1 — I 2,,_ I^Zl (E2) Here | AZ | represents the determinant of the system characteristic and Ei represents the transform of the total driving formes including initial currents or voltages (i.e., boundary conditions). Operationally, a capacitance voltage does not differ from a step voltage and the initial current appears as an impuse function. BIBLIOGRAPHY Berg, E. J. — 1936 — Heavyside’s Operational Calculus, 2nd ed. New York, McGraw Hill Book Co., Inc.: xv, 258, diagrs. Campbell, G. A., and R. M. Foster — 1948 — Fourier Integrals for Practical Appli¬ cations. New York, D. Van Nostrand Co., Inc.: 177, tables. Gardner, M. F., and E. J. Barnes — 1942 — Transients in Linear Systems, Vol. I (Lumped-Constant Systems). New York, John Wiley and Sons, Inc.: v, 389, tables, diagrs. McLachlan, N. W. — 1939 — Complex Variable and Operational Calculus with Technical Applications. Cambridge, The University Press: xi, 355, illus., diagrs. Starr, A. T. — 1946 — Electric Circuits and Wave Filters, 2nd ed. London, Sir 1. Pitman and Sons, Ltd.: xii, 475, illus., fold, tab., diagrs. THORSTEIN VEBLEN AND PRIMITIVE SOCIETY MURRAY E. POLAKOFF The University of Texas All of Thorstein Veblen’s social philosophy and study of cultural growth and evolution, as well as his conception of human nature, is marked by a sharp dualism. This dualism can be accurately subsumed under the twin concepts of "industry” and "business.” An explanation of these concepts is in order if we are to understand and appreciate the genius of Veblen, as well as make use of these distinctions in the study of primitive institutions and cultures. NATURE OF INDUSTRY Veblen finds rooted in human nature a workmanlike disposition to find merit in any work that serves the common good. This instinct of workman¬ ship is a universal property and finds expression in an abhorrence of waste and futility. The making of material goods in terms of this instinct is not physically or spiritually repulsive. On the contrary, pleasure is derived from such endeavors, the ends of which are the common good. On the basis of this instinct psychology, Veblen proceeds to construct an evolutionary sequence of cultural growth. The stages through which mankind and its institutions have passed are divided into four phases: the Golden Age of Savagery, the Predatory Barbarian Economy, the Fiandicraft Economy and, finally, the age of the Machine Technology. Veblen remarks in his Theory of the Leisure Class that the evidence for his hypothesis is "in great part drawn from psychology rather than from ethnology,” and a par¬ ticularly astute student of Veblen feels that Veblen’s stages or sequences are merely methodological fictions used by the latter to throw into relief the values of a pecuniary and business culture. (Dorfman, 1929, p. 510) Be that as it may, this paper is concerned with discovering the degree of validity which Veblen’s constructs have when applied to a study of primi¬ tive cultures and their functionings. Veblen states that in "Savage” culture, the instinct of workmanship works itself out fully without interference from or conflict with those traits to be described under the term "business.” It is important, therefore, to follow Veblen in his description of such a culture— -real or imaginary — and to discover those traits of human nature which such a culture fosters. In such a society there is no leisure class, i.e., a group which does not perform useful (industrial, material) work. There seems to be an almost complete absence of private property, and the people are peaceable and guileless. Force and fraud are relatively unknown, and no invidious distinc¬ tions are drawn in terms of rank or success. The whole leisure class ap¬ paratus: priestly cult, warrior caste, inheritors of political power, hierarchical ranks and designations of status— these are notable by their near or com¬ plete absence. The economy is a subsistence economy which leaves little room for anything but the closest attention to the production of material goods. 106 1953, No. 1 March Veblen and Primitive Society 107 Carried into our culture, this instinct of workmanship manifests itself in the production of material goods and the development of the state of the industrial arts and of science. For in the remaking and transforming of inert matter into serviceable commodities, matter-of-fact habits are de¬ veloped and fostered, and this "^cultural incidence of the machine process” results in cause-and-effect explanation of all phenomena, natural and human. The result is the scientific attitude and the growth of technological inven¬ tions. The class most in contact with this process in modern civilization is that group composed of scientists, engineers, technicians, etc., and it is to this group that Veblen makes his appeal. This class is interested in the fur¬ ther development of technology and in the making of more and more service¬ able articles for the community as a whole. NATURE OF BUSINESS The antithesis of Veblen’s "industry” is to be found in his description of "business.” The latter, like workmanship, is an instinctive disposition and consists of a powerful desire to admire and defer to persons of achieve¬ ment and distinction. The distinction which is admired and deferred to may often be nothing more to the point than a conventional investiture of rank attained by the routine of descent as, for example, a king, or by the rou¬ tine of seniority as, for example, a prelate. Thus, there is a dualism in hu¬ man nature itself which finds expression in all stages of human civilization. The instinct of workmanship and the propensity to emulation are incom¬ patible for Veblen and yet both are part of man’s innate heritage. Both are to be found in any stage of human evolution, though in any particular culture one is more prominent than the other. Habituation to one or the other is the stuff of human institutions, and since Veblen finds the emula- tory propensity to be the dominant one in all institutions since the Golden Age of Savagery, to that extent "industry” has been overshadowed by "business.” The source of social conflict lies in the adjustment of institu¬ tions to the technological and economic base of society. Since technology is cumulative and continuous and, for Veblen, the touchstone of all value, institutions which do not adapt themselves to these changes are backward and reactionary and to that extent hinder the development of these forces. The origin of "business” institutions and the victory of the emulatory propensity is to be found in his analysis of the Predatory Barbarian stage of cultural evolution. This stage is marked by an economy in which a surplus over subsist¬ ence is produced which allows for a sizeable group of the population to di¬ vorce itself from the main occupation of producing serviceable goods for the whole community. Private property receives its greatest stimulus, and its origin is the ownership of human beings (slaves) first of all, and later the direct acquisition of all types of goods. Here for the first time we find an aversion to useful labor in contrast to such honorific employments as are dealt with by the warrior caste, the priestly cult, the legatees of political power, etc. Predation, animosity and warfare take the place of labor and peaceful sedentary pursuits in the societal scheme of values, and with the former goes the resort to fraud and guile. The emulatory propensity receives its full flowering in the invidious distinctions which are attached to rank and status. Anthropomorphism and animism take the place of the matter- of-fact attitude, and prowess and propitiation of spiritual residues residing in inert matter become all-important. Success (whether by guile, force, 108 The Texas Journal of Science 1953, No. 1 March wealth, magic) become the all-pervasive standards in such a society and mark off this group from those who conceive of life as the production and supplying of greater and greater material goods for the commodity. Teleology takes the place of the cause-and-effect attitude toward life. Many of the goals and standards of conduct v/hich are first to be seen in the Predatory Barbarian stage of human culture are incorporated into the Machine or Technological age. Of course, groups shift in relative power; for example, in our society the businessman is more important than the priestly or political groups which had primacy in an earlier age. But the same residues to be found in the Barbarian stage are present in ours, although in different form. For Veblen sees ours as .i pecuniary, acquisitive culture, using power and guile to achieve self-regarding ends. Honorific distinction is attached to the person of the businessman in contrast to those segments of the community which are engaged in the making of serviceable products. And yet, as with the other honorific groups mentioned previously, the busi¬ nessman is functionless and merely an absentee owner with respect to the process of material production. His goal is the making of profit, of drawing a differential income from the produce of the community. He reaps where he has not sown. In fact, in the pursuit of these profits he retards produc¬ tion, since he only "produces” up to the point of greatest marginal net revenue. The pursuit of profits, therefore, interferes with the further use of the technological apparatus, and so, in Veblen’s eyes, the businessman is reactionary in terms of the developing productive forces, a saboteur of the industrial process through his limitations on production. Thus, the so¬ cial conflict in modern society is to be found in terms of the restriction of production through monopoly (business) and the continually increasing productivity of modern industry (whose human counterparts are the engi¬ neers, technicians, etc.). To the extent that the latter accept the folklore of the business commodity, to that extent conflict is held in abeyance. Also, as with other non-functional groups, invidious distinctions are drawn by the businessman through the display of conspicuous leisure and consumption. The latter increase the dignity and rank of the businessman, since they serve as effective counterweights to productive labor which, in a business civilization, or in any status society, is considered an inferior occupation. Parenthetically, it may be remarked that Veblen underrated the imma¬ nent force of the self-regulating market mechanism and overvalued the pres¬ tige factor as the integrative force through which our market economy was to be explained. Be that as it may, one of the great contributions of Veblen was his underlining of the importance of prestige or emulation in the work¬ ings of any society and its economy, and the development of this concept into a body of consistent thought. We now turn to the study of three primitive cultures and to the role played by the prestige concept as an inte¬ grating factor in these societies. the KWAKIUTL INDIANS Veblen’s analysis of the role of prestige in primitive society seems to fit Kwakiutl Indian culture perfectly. As Irving Goldman says in his essay on the Kwakiutl: All the social relations among the Kwakiutl are keyed to the principle of rank, and each individual of any status in the community is motivated by an obsessive drive for prestige. The social stratification ... is, on the Northwest Coast, carried to an extreme degree in terms not of material goods but of prerogatives. (Goldman, 1937, pp. 183-184) 1953, No. 1 March Veblen and Primitive Society 109 Subsistence. It is well to mention first of all that the Kwakiutl Indians inhabit a region renowned for the abundance of its sea life, and so the prin¬ cipal economic pursuit of the Kwakiutl is fishing. Redistribution is the economic form used with regard to subsistence, with half the catch given to the chief of the mimaym, or kinship unit, who redistributes it to all who need food during the winter, when economic life is suspended. It is always the responsibility of the chief to provide for his people when they are in need. The other half is used to feed the household of the men who caught the fish. Members of the numaym cooperate also in the ownership and ex¬ clusive use of hunting, fishing, and berry-picking territory. But given this rich and fertile territory, only a relatively small proportion of the Kawkiutl’s time is devoted to food-getting and industry. The means of subsistence being amply assured through a provident nature, most of the time-consum¬ ing activities of the Kwakiutl seem directed to the attainment of ever greater prestige and honorific titles, to the detriment of continued increases of serviceable goods. Prestige. Says Goldman: Upon an conomic base of comparative plenty, the Kwakiutl have developed a system of economic exchanges that bears little relation to the problem of existence. Property is accumulated only to be redistributed or destroyed in a game in which prestige and self-glorification are raised to an egoman- iacal pitch. More important even than material property as counters of prestige are the jealously guarded honorific names, titles, family traditions, and ceremonial prerogatives. Material property is valued only to the ex¬ tent that it can procure or validate these prerogatives and names. The social structure reflects the great valuation of immaterial property in Kwakiutl life. (Goldman, 1937, p. 180) The striking emphasis is upon rank. All tribes, numayms, and families are graded according to a strict pattern. Within the tribe each individual is further classified as a nobleman, commoner, or slave. The nobility are the first-born of families of rank; the commoners are the younger sons and daughters. Religion too, according to Goldman, is subordinated to the drive for rank and prestige, contact with the supernatural being based upon strictly owned, inherited, or otherwise validated prerogatives. Social stratification is so marked that even the t-tibes and, within them, the numayms and families are not equal in rank. All are ranged in a hieararchy of values the way their ancestors were supposed to have been ranked. Gold¬ man states: The possession of a title, however, does not in itself give the individual social prestige. Each claim to nobility must be validated by the distribution of property, blankets, boxes and by the giving of feasts during which great quantities of valuable oil are conspiciously destroyed. Above all, an individual gains prestige by crushing a rival ... It is a war in which prop¬ erty is the weapon. (Goldman, 1937, p. 184) The name given to these ceremonial, prcperty-destroying and property- redistributing feasts is the potlatch, and its chief purpose is to enhance the prestige and rank of a tribe, numaym or individual by outdoing, through a display of conspicuous waste or conspicuous wealth, its rival in the matter of prodigality. The potlatch plays an indispensable role in the drive for prestige. Kinship itself is tied in with the prestige factor since status is deter¬ mined by the order of birth and birth itself. Rank is hereditary and classes fixed. Marriage i$ the occasion for ceremonial along prestige lines, father- 110 The Texas Journal of Science 1953, No. 1 March in-law and son-in-law displaying their high rank by indulging in an elabo¬ rate potlatch. Even murder is integrated into the Kwakiutl value scheme, since the former is recognized as a valid method of adding to one’s prestige and rank. A man claims as his own all the names and special privileges of his victims. Whereas collective notions may have entered into the subsistence econ¬ omy and the use of material property, the paraphernalia of nobility are strictly individualistic. In the Veblenian scheme, individualism is strongly tied up with rivalry and self-regarding motives, and this seems especially true of Kwakiutl society. With regard to religion, Goldman states: As the secular organization of the Kwakiutl is built around rivalry for pres¬ tige and the display of honorific prerogatives, so is the religious . . . Kwakiutl ceremonialism ... is directed entirely toward individualistic ends . . . Moreover, consistent with the emphasis upon rank, each of the dances is ranked in a hierarchical system. It is these dances, which confer the most valued Kwakiutl prerogatives, that are obtained through inheritance from the mother’s line or through the murder of the previous owner. ( Goldman, 1937, pp. 198-199) In general, the religious organization of the Kwakiutl parallels the secular. As there are titles of nobility, so are there recognized hieararchical distinctions in the use and ownership of religious prerogatives. Religious pre¬ rogatives are but another aspect of the nobility and power of an individual of rank. What about the commoner in this value scheme? Goldman continues: What is accepted behavior for a chief or a nobleman is, however, denied the commoners . . . The commoner’s place is primarily on the sidelines . . . Yet each commoner in his own right and within the limits imposed upon him by his lack of noble prerogatives behaves in precisely the same way as a chief. Kwakiutl society is permeated to the core with the urge for per¬ sonal glory. (Goldman, 1937, p. 207) Thus, every aspect of Kwakiutl life is oriented to the basic drive for prestige, and the emphasis upon rank is consistently reflected in social re¬ lations; in marriage, in religion, and in law. Prestige in Kwakiutl society is the great integrating factor holding the social fabric together. Kwakiutl life offers the closest resemblance in its workings to the "business” analysis of Veblen. TOLOWA-TUTUTNI CULTURE Tolowa-Tututni culture also lends assistance to Veblen’s ideas on emu¬ lation, although the prestige factor operating through the medium of wealth is not as integrative in terms of social cohesion as in Kwakiutl society. Never¬ theless, it does permeate and shape a large part of social behavior in that society. Subsistence. Like the Kwakiutl, the Tolowa-Tututni have a rich sub¬ sistence provided by a bountiful environment. Privately-owned fishing sites are available to any industrious individual. Interchange of goods is through the medium of barter, although the favorable environment makes even barter a relatively minor activity. In addition, food is shared by the provi¬ dent with the improvident within the village group. The Veblenian concept that industry brings forth as some of its concomitants, generosity and con¬ cern for the public welfare, certainly holds good in this realm of Tolowa- Tututni culture. 1953, No. 1 March Veblen and Primitive Society 111 Prestige. Tolowa-Tututni culture is permeated with social prerogatives and status values. It includes a range of phenomena from wives to formulae for supernatural compulsion. It embraces mourners' privileges and innumer¬ able personal dignities. Money, represented by dentalium shells, serves as the visible symptom of wealth in this society and wealth values are associated with social status. Interestingly enough, money does not serve as a medium of exchange in the subsistence part of the economy, and haggling in terms of exchange and driving a hard bargain are features of the prestige part of the economy alone. Unlike subsistence, wealth, through the medium of money, is the source of all social advantages and pre-eminences. Social relations are permeated with the concept of wealth. All injuries, whether insult, mayhem, or murder are torts for which compensating pay¬ ments can buy atonement. And wealth grants rights of judgment as well. Thus Cora DuBois says: Social equilibrium was the vested interest of the rich man who dominated each village . . . The rich man functioned as a state surrogate. (Dubois, 1936, p. 55) Slavery is a result of debt obligation; and since debt can only be in¬ curred in the realm of prestige economy, slaves become a source of pres¬ tige ostentation. They are the symbols of money once owned and loaned. Similarly marriage is a function of the prestige economy. Marriage only functions through bride prices, and the price paid reflects the social status of the bride or bridegroom's parents. Thus the impregnation of the institution of marriage with the dominant wealth preoccupations serve to color sex and familial relationships. Education is also linked with the prestige economy, since the education of both sexes stresses the desirability of wealth. Sexual preoccupations are to be suppressed until wealth is acquired and status obtained. Similarly, religion is impregnated with financial emphasis. Shamans and mourners receive payments for their services, and so enter into the prestige economy. In all the aspects of society into which the wealth and prestige factors enter, there also enter their Veblenian concomitants, namely, rivalry, sharp dealing and self-seeking. Whereas generosity is to be found in the subsistence part of the economy, suspicion and haggling prevails in the prestige sector. Since the acquisition of wealth is basic for social status, and since status is the center of all activities regarded as meritorious in Tolowa-Tututni so¬ ciety, the aforementioned type of behavior is readily understandable. Those parts of the society which have not been integrated into the wealth complex are the non-acquisitive character of warfare and the sub¬ merging of private property in the interest of the kin group and its use outside of its own kin in the subsistence part of the economy. All in all, however, the integrative force of wealth in Tolowa-Tututni society is considerable. Since the striving for wealth, however, in no way adds to serviceable output, this culture falls into the Veblenian milieu. Dentalia do not add to material output, but they do add honorific distinc¬ tions and status claims, and the latter are the mainspring of Tolowa-Tututni behavior and culture. 112 The Texas Journal of Science 1953, No. 1 March MANUS CULTURE Manus culture does not fit many of the basic requirements postulated by Veblen. There is no leisure class in this society, and rank and status are directly integrated with industry. Recognition goes to a man in terms of the amount of wealth which has passed through his hands, and in Manus society this can only be achieved through tremendous exertion and energy. Subsistence and prestige work together and not at the expense of one another. Subsistence. The Manus inhabit land which is limited to a few rough coral outcrops and platforms of coral rubble. Without land, without any farinaceous food, dependent upon barter for the very tools and utensils with which they earn their livelihood, the Manus are up against an exacting en¬ vironment. Although the Manus are the most disadvantageously placed of all the tribes in that part of the archipelago, they are the richest and have the highest standard of living, and this is the result of the drive for prestige. Prestige. With regard to continuous labor, Margaret Mead says: The forces which keep this continuous game of exchanging going are sev¬ eral: In the first place, no one can ever retire on his laurels. Every economic reward of leadership is expressed dynamically, 'I have done and I am doing.’ . . . The minute that a man is no longer an active participant he loses all standing in the community, and may even be taunted with the fact that he was once a big man. (Mead, 1937, p. 217) As for these equal exchanges, they are the method by which the goods of the community are distributed. But more than this, prestige is so inter¬ woven with industry that the actual amount of goods in existence depends upon the number of leaders. It varies with their enterprise, intelligence, and aggresiveness. In fact, the need for tremendous expenditure of effort is so great as a direct result of the prestige system that it is a rarity indeed when any man lives beyond the age of fifty. There are also those independents who have chosen not to follow the game of affinal exchanges and ideas of prestige derived from these ex¬ changes and are mainly self-supporting. But the high standard of living is a direct result of such exchanges, which in turn are the avenues through which rank and status emerge. Here we observe a society in which the dualism of Veblen really does not apply. To be sure, there are prestige motives in play, but these depend upon the greatest amount of productive and continuous labor. No leisure class can exist in such a society and, in fact, none does. CONCLUSION Most cultures exhibit features of industry and prestige. This is almost axiomatic, inasmuch as subsistence is necessary for existence, and every society has a scheme of values in which rank and status enter to some de¬ gree as concomitants. Admiting the existence of these twin motives, how¬ ever, is not the same as admitting that they then fall into the Veblenian scheme. As in the case of Manus society, industry and prestige may directly enforce one another. There is no universalitv to Veblen’s propositions. Veb- len’s weakness consists in thinking of technology as being a sufficient touch¬ stone unto itself. Political, social and moral values permeate any social order, and the concept of serviceability in and of itself cannot be set down in a 1953, No. 1 March Veblen and Primitive Society 113 societal vacuum. Culture enhances social living, and where there is culture there are value schemes and societal distinctions and gradations. To the extent that these values are antagonistic to productive effort, to that extent Veblen makes a most important contribution. LITERATURE CITED DORFMAN, Joseph — 1939- — On institutional economics. Science and Society 3(4) 509-514. DuBoiS, Cora — 1936 — The wealth concept as an integrating factor in Tolowa- Tututni culture. In: Essays in Anthropology in Honor of A. L. Kroeber, pp. 49-65. Berkeley, California. Goldman, Irving — 1937 — The Kwakiutl Indians of Vancouver Island. In: Mead, Margaret, Cooperation and Competition Among Primitive Peoples., pp. 180- 209. New York and London. Mead, Margaret — 1937 — The Manus of the Admirality Islands. In: Mead, Mar¬ garet, Cooperation and Competition among Primitive Peoples, pp. 210-239. New York and London. KEYS TO THE LARVAE OF TEXAS MOSQUITOES WITH NOTES ON RECENT SYNONYMY ^ IE THE GENUS CULEX LINNAEUS OSMOND P. BRELAND The University of Texas INTRODUCTION The first paper in this series (Breland, 19 5 2) dealt with the genera of mosquitoes found in the state and with the species of Aedes Meigen. The present paper is concerned specifically with the species of the genus Culex Linneaus. Synonymies and name changes involving several species have occurred during the past few years, and in some cases the status of certain mosqui¬ toes and their correct names are still unsettled. Bohart (1948) has made a study of the species of the subgenus Neoculex. He discovered that the species in the United States known as apicalis Adams really consists of a complex of several distinct species. He concluded that territans Walker, rather than apical/s, is the correct name for the species of this complex that occurs in Texas and adjacent areas. - - — > PLATE I Heads of CpJex mosquito larvae (dorsal view) showing larval hairs and other structures used in identification. Different possible conditions of certain key features are illustrated in the two diagrams as indicated below. Only those structures of im¬ portance in identificaton have been labeled. Abbreviations A Antenna. AT Antennal hair. In this diagram, the antennal hair arises from a constriction in the outer third of the antenna. PA Preantennal hair. LHH Lower head hair. The hair is single in this figure. UH Upper head hair. Note that the upper head hair is multiple and much shorter than the lower head hair. Figure B Abbreviations A Antenna. AT Antennal hair. Here the antennal hair arises near the middle of the antenna. LHH Lower head hair. In this diagram the lower head hair is barbed and multiple. PA Preantennal hair. UH Upper head hair. The upper head hair is barbed, multiple and longer than the lower head hair. ^ Supported by the University of Texas Re.search Institute. Drawings by Miss Grace Hewitt. 114 1953, No. 1 March Larvae of Texas Mosquitoes 115 There is still no general agreement as to the correct name of the mos¬ quito that has been called the southern hcmse mosquito. The two most commonly used names for this species are Culex cpiinquefasciattis Say and C. fatigans Wiedmann. This mosquito is widely distributed throughout the tropical and subtropical areas of the world, and it has been considered in the publications of many different groups of workers. Most Americans use qiunqjiefasciatus, while taxonomists from other regions have usually referred to the same species as fatigans. This latter practice follows the action of Edwards (1932), who adopted fatigans rather than qninquefasciatus. This procedure was based upon the possibility that Say may have applied qninqne- fasciatus to another species rather than to the one in question. However, this possibility has not been proved. The nivme, quinqtiefasciatns, was used 116 The Texas Journal of Science 1953, No. 1 March I in 1 823, while fatigans was not published until 1828 (Carpenter et al: 1946). For these reasons, quinquefasciafus will be used in the present paper. Two species included in the key deserve brief comment. Culex t hr iam¬ bus Dyar, originally described from Texas has been considered as both a subspecies (Dyar, 1928) and as a synonym of C. stigmatosoma Dyar (Math- eson, 1944). Galindo and Kelly (1943), hov/^ever, restored C. thriambtis to full specific rank. So far as could be determined, there has not been a suffi- B LH 1953, No. 1 March Larvae of Texas Mosquitoes 117 cient amount of work done on these mosquitoes in this area to justify posi¬ tive conclusions at this time. The writer as well as other workers have collected larvae in Texas that fit the description of C. thriambm^ but large series of correlated adults have not been reared for study. Griffith (1952) reports both thriambus and stigmatosoma from Oklahoma, and it might well be that both species occur in Texas. At the present state of our knowledge, some species of Culex larvae are difficult to distinguish with certainty from similar forms. This is also true for species of Aedes previously considered, as well as for the larvae of certain other genera. It is thus very desirable that additional studies be made in an effort to discover additional and more obvious key features for the determination of closely related species. The writer will greatly appreciate hearing from other workers who may have suggestions for the improve¬ ment of the keys used in this series of papers. The heads and terminal segments of two Culex larvae are figured, but they do not represent any specific species. As indicated in the explanation of plates, different possible conditions of some important key features are included in the two figures. Some recent publications of importance other than those specifically cited are listed in the bibliography. KEY TO THE SPECIES OF CULEX LARVAE IN TEXAS 1. Pecten teeth continued distally by a row of 4 or 5 large spines _ interrogator D. & K. Pecten teeth not continued distally by a row of spines _ 2 <■ - — - - — PLATE II Terminal abdominal segments of Culex mosquito larvae (lateral view) showing structures used in identification. Different possible conditions of certain key features are illustrated in the two diagrams. Only those structures of importance in identifica¬ tion have been labeled. Figure A Abbreviations CS Comb scales or comb. Here the scales are arranged in a single irregular row. The individual comb scales are thorn-like. LH Lateral hair of the anal segment. In this case it is a single hair. P Pecten teeth or pecten. S Siphon or air tube. In this diagram the siphon is considered stout and 4 to 5 times as long as its diameter (usually expressed in keys thus; siphon 4 or 5 yi). SH Siphonal hair tufts, ventral or subventral hair tufts. The subapical tuft is out of line. In this case, none of the tufts arise within the pecten. Figure B Abbreviations Comb scales or comb. The comb scales are arranged in a triangular patch. CS The individual comb scales are rounded apically and fringed with subequal teeth. LH Lateral hair of anal segment. It is double in this case. P Pecten teeth or pecten. S Siphon or air tube. In this diagram the siphon is considered slender and 6 to 7 times as long as its diameter (usually expressed in keys thus: siphon 6 or 7 : 1). SH Siphonal hair tufts; also called ventral and subventral tufts. None of these tufts are out of line. The first two tufts arise within the pecten. 118 The Texas Journal of Science 1953, No. 1 March 2. At least 1 hair tuft of siphon arising within pecten _ 3 None of hairs of siphon arising within pecten _ 6 3. Siphon with 6 to 9 pairs of hair tufts _ 4 Siphon with only 3 to 5 pairs of hair tufts _ 5 4. Comb scales few, arranged in a single, sometimes irregular row; siphon 3 or 4: 1 _ _ _ _ pilosns D. & K. Comb scales many, arranged in a triangular patch; siphon 7 or 8: 1 _ _ chidesteri 5. Siphon with 3 pairs of hair tufts, the middle one out of line _ _ _ declarator D. & K. Siphon with 5 pairs of hair tufts, the subapical tuft out of line _ : _ stigmatosoma Dyar 6. Both upper and lower head hairs with more than 2 branches _ 7 At least one set of head hairs, and sometimes both, single or double _ 13 7. Siphon with several spines or spikes near apex _ _ _ _ coronator D. & K. Siphon without subapical spines _ 8 8. Hairs on siphon mostly single _ _ 9 Hairs on siphon mostly double or multiple _ _ _ 10 9. Antennal tuft arising near middle of antenna _ restuans Theo Antennal tuft arising near outer third of antenna _ _ _ _ _ _ t hr iambus Dyar 10. Siphon with 5 or 6 pairs of many-haired tufts, none greatly out of line _ i _ farsalis Coq. Siphon with 4 or 5 pairs of tufts, often with few hairs; subapical tuft out of line _ _ _ 11 1 1. Siphon stout, 4 or 5 : 1 ; lower head hairs usually with 5 or more branches _ quinqnefasciatns Say Siphon slender, 6 or 7 : 1 ; lower head hairs with 3 or 4 branches _ _ _ 12 12. Lateral hair of anal segment usually single; thorax covered with small dark spicules _ _ _ nigripalpus Theo. Lateral hair of anal segment usually double; thorax without spicules _ salinarms Coq. 1 3 . Both upper and lower head hairs usually long and single, rarely double on one or both sides; upper head hairs 2/3 to 3/4 as long as lower _ _ _ territans Walker Upper head hairs double or multiple, much shorter than lower - 14 1953, No. 1 March Larvae of Texas Mosquitoes 119 14. Comb scales arranged in an irregular single or double row; individual comb scale thorn-like under high power _ _ _ _ erraticMs D. & K. Comb scales arranged in several rows or a triangular patch; individual comb scale rounded apically and fringed with sub-equal spinules _ _ 15 15. Upper head hairs with more than 3 branches _ inhibit ator D. & K. Upper head hairs usually double, rarely with 3 branches _ _ 16 16. Individual comb scale elongate; teeth of pecten fringed on one side with many small spinules _ peccator D. & K. Individual comb scale short and ovoid in shape; teeth of pecten with several large spines on one side _ _ _ _ aborninator D. & K. LITERATURE CITED Bates, Marston — 1949 — The Natural History of Mosquitoes. The Macmillan Com¬ pany, New. York. Bohart, Richard M. — 1948 — The subgenus Neoculex in America north of Mexico (Diptera, Culicidae). Ann. Ent. Soc. Amer. 41: 330-345. Breland, Osmond P. — 1952 — Keys to the larvae of Texas mosquitoes, with notes on recent synonymy 1. Key to the genera and to the species of the genus Aedes. Texas Journ. Sci. 4: 65-72. Carpenter, Stanley J., Middlekauf, Woodrow W., and Chamberlain, Roy W. — 1946 — The mosquitoes of the southern United States east of Oklahoma and Texas. The University Press, Notre Dame, Ind. Dyar, Harrison G. — 1928 — The mosquitoes of the Americas. Carnegie Inst. Wash., Pub. 387 . Eads, R. B. — 1943 — The larva of Culex ahomtnator Dyar and Knab. Journ. Eco. Ent. 36: 336-337. Eads, R. B., Menzies, G. C., and Ogden, L. J. — 1951 — Distribution records of West Texas mosquitoes. Mosquito News 11: 41-47. Edwards, F. W. — 1932 — Diptera, Earn. Culicidae, in P. Wystman, Genera Insector- ium, fas. 194. Bruxelles: V. Verteneuil and L. Desmet. Galindo, Pedro, and Kelly, Thomas F. — 1943 — Culex {Culex) thriambus Dyar, a new mosquito record from California. Pan-Pacific Ent. 19: 87-90. Griffith, Melvin E. — 1952 — Additional species of mosquitoes in Oklahoma. Alos- quito News 12; 10-14. Joyce, C. R. — -1948 — -Culex chidesteri Dyar (Diptera, Culicidae) at Brownsville, Texas. Mosquito News 8: 102-105. Matheson, Robert — 1944 — Handbook of the mosquitoes of North America, 2nd. Ed. Comstock Pub. Co., Ithaca, New York. Randolph, Neal M., and O’Neill, Kelly— 1944— The Mosquitoes of Texas. Bull. Texas State Health Department. Rueger, Myrtle E. and DrucE, Stennette — 1950 — New mosquito distribution records for Texas. Mosquito Neivs 10: 60-63. Thurman, D. C., Ogden, L. J., and Eyles, Don E.— 1945— A United States record for Culex interrogator. Journ. Eco. Ent. 38: 115. ARTHROPOD-BORNE DISEASES IN TEXAS IN 1950 R. B. EADS AND R. D. GRIFFITH Bureau of Laboratories State Department of Health, Austin, Texas An impressive array of bacterial and parasitic diseases are known to be transmitted to human beings by insects and related arthropods. This paper is concerned with the more important of these diseases in Texas during 1950. These data were obtained from research projects and Morbidity Re¬ ports of the State Department of Health. DYSENTERY During 1950 there were 37,52 5 cases of dysentery of bacillary, amoe¬ bic and viral origin reported to this Department by Texas physicians. Re¬ peated laboratory experiments have demonstrated that enteric infections can live on the bristly bodies and within the intestines of such omnivorous in¬ sects as flies and cockroaches. Since they frequent almost every conceivable type of organic matter, including human and animal excrement and human foodstuff, it is felt that insects, principally house flies, are responsible for a large number of the dysentery cases. Studies on community-wide fly control by the Public Health Service and State Department of Health in the Rio Grande Valley emphasize this point. In fly controlled areas a sig¬ nificant reduction of Shigella dysentery was effected and Salmonella cases were reduced. In the face of our present natural recession of malaria and typhus, insect transmitted dysentry is probably our most important arthro¬ pod-borne disease. « VIRUS ENCEPHALITIS Encephalitis, or inflammation of the brain, may be due to a wide va¬ riety of causative agents such as physical or chemical injury, bacterial or parasitic infection, tumors or one of several viral agents. Three viruses which have been shown to be endemic in the United States are of concern in this discussion, since arthropods act both as reservoirs and transmitting agents. Involved are St. Louis encephalitis, eastern equine encephalitis and western equine encephalitis. The two latter viruses are the causative or¬ ganisms of a highly fatal disease of horses, thousands formerly being affected annually in the United States. Human cases frequently accompany or follow outbreaks in horses. The following species of arthropods have been found naturally infected with the western strain: Mosquitoes — -Culex far sails, C. pipiens, Culiseta in- ornata, Anopheles freeborni, Aedes dorsalis and Mansonia perturbans; Mites — Dermanyssus gallinae, D. americanus, Liponyssus sylviarmn and L. bursa; and the bug, Triatoma sanguisuga. Mansonia perturbans mosquitoes have been found naturally infected with the eastern strain of encephalitis. Num¬ erous species of insects, including several genera of mosquitoes, mites, ticks and other blood sucking arthropods have been shown capable of transmitting both the eastern and western strains experimentally. 120 1953, No. 1 March Arthropod-borne Diseases 121 Culex iarsalis mosquitoes and the chicken mite, Dcrmanyssus gallinae, have been taken which were naturally infected with both St. Louis and western equine encephalitis. Several species of mosquitoes, the tick, Derma- centor variabilis, and the mite, Dermanyssiis gallinae, have transmitted St. Louis encephalitis under laboratory conditions. Birds, particularly domestic poultry, are susceptible to these viruses and apparently serve as important reservoirs All three strains have been demonstrated in man or horses in Texas. However, diagnostic difficulties have prevented an adequate appraisal of the viral encephalitides in the state. No cases received laboratory confirmation by this Department during 1950. DENGUE This noncontagious, infectious disease characterized by headache and severe pains in the extremities is of viral etiology. Aedes mosquitoes of the subgenus Stegoinyia are involved in its transmission throughout tropical and subtropical regions of the world. It occurs in epidemic form coincident with the appearance of large populations of mosquitoes, particularly Aedes aegypti. In 1922 there were over 60,000 cases reported from Galveston and Houston alone, and an estimated 5 00 to 600,000 in Texas as a whole. The most recent outbreak was in the Rio Grande Valley and surrounding area in 1941. The 5 00 cases reported were thought to be but a fraction of the total cases. Dur¬ ing 1950, Texas physicians reported 24 cases of dengue to this Department. It is of interest to remark that the difficulties in diagnosing dengue have been materially lessened by the production of specific antigens for use in complement-fixation testing. A blood specimen taken early in the illness and another late in the illness are studied for evidence of increase in sero¬ logic titer. AMERICAN SPOTTED FEVER This disease, as with all rickettsial diseases with the exception of epi¬ demic typhus, is primarily a disease of animals (principally rodents and rabbits) and the tick vectors are parasites of these animals that function in the maintenance and perpetuation of the disease agent in nature. Since the tick is not a habitual parasite of man, the disease does not, as a rule, appear in epidemic form. The descriptive part of the name of this disease is derived from the characteristic irritating rash which accompanies it. Tick bite is the usual source of human infections of spotted fever. The disease is known to occur in Canada, Mexico, Columbia, Brazil and at least 43 of the 48 states in the United States. Three species of ticks are proven vectors to man in this country, Dermacentor andersoni, D. variabilis and Amblyomma americanum. Other ticks, particularly Haemaphysalis leporis- pahistris, transmit the infective agent among animals in nature. In Texas, the "lone-star” tick is incriminated as the primarv vector to man on epi¬ demiological grounds. This species has not been found naturally infected in Texas, but positive pools of A. americanum have been recovered just across the border in Oklahoma. There are usually 3 or 4 cases of spotted fever ? year reported in Texas. However, in 195 0 only one case has been made known to us. 122 The Texas Journal of Science 1963, No. 1 March Q FEVER This Department has maintained an active interest in the rickettsial disease, Q fever, since the outbreak of 5 S cases in Amarillo in 1946 represent the first naturally acquired sizeable outbreak of infections in the United States. Human cases are characterized by remittent fever, headache and malaise, and are often confused with influei'za or atypical pneumonia. The mortality rate is low. The causative organism, Coxiella burnetii, was first isolated from the tick, Dermacentor andersoni, in Montana in 193 5, although human cases occurred as early as 193 3 in Queensland, Australia. It has now been shown to have a world wide distribution. California and Texas have recorded a majority of the United States cases. In this country, natural infections have been demonstrated from: 7 species of ticks, including the "lone-star” tick, Amblyomma americanum, which is prevalent in Texas; blood, milk and tissue of cattle, sheep and goats; and from man. Since 1946, at least 86 human cases have received confirma¬ tion by this Department. Positive raw milk samples have been obtained from 8 dairies. Surveys of the occurrence of Q fever in livestock suggest the endemicity of the disease in the southern part of the state. It is felt that ticks and other arthropods are of little consequence as sources of human infections. Epidemiological evidence indicates that cattle, sheep and goats are of primary importance in human infection either by inhalation of particles of dust contaminated with infected milk or excretory products, by direct contact with infected tissue, or by drinking raw milk containing the rickettsiae. TYPHUS Texas is in the heart of the endemic typhus region; 1,452 cases of this rickettsial disease were reported in 1943, 1,740 in 1944 and 1,83 6 in 1945. These cases represented almost a third of the entire number occurring in the United States. There has been a steady decline in incidence since 1945, with only 222 cases being reported in 1950. Domestic rats and mice are the reser¬ voirs of endemic typhus and rat fleas, lice and possibly mites transmit the rickettsiae from rodent to rodent and to man. During studies on this disease made by the State Department of Health in Lavaca County in 1945, 3,962 Xenopsyila cheopis fleas were tested for typhus in 121 pools, with 39 pools positive; 659 Leptopsylla segnis fleas in 32 pools showed 8 pools positive; and 1,726 Echidnophaga gallinacea fleas in 5 0 pools yielded 4 positive pools. This is respectively 32, 2 5 and 8 percent posi¬ tive pools. PLAGUE The first report of the recovery of the plague organism, Pasteurella pesfis, from Texas rodents was made in 1921. Infected Norway rats, Rattus nor- vegicus, were recovered during the 1920-21 outbreak of human cases in Galveston, Beaumont and Port Arthur. Approximately 18 human cases were diagnosed. No additional rodents or their fleas were found infected in Texas until 1946, when the Public Health Service demonstrated the presence of plague bacilli in 8 different pools of fleas from ground squirrels, prairie dogs, kangaroo rats and grasshopper mice in Cochran County and in prairie dog fleas from Dawson County. 1953, No. 1 March Arthropod-borne Diseases 123 A cooperative plague research project was conducted in west Texas from 1947-49 by the State Department of Health and Public Health Service. Plague positive fleas or rodent tissue were recovered in the counties of Daw¬ son, Cochran, Gaines and Yoakum. Subsequent to these findings, survey crews of the Public Health Service have taken plague positive fleas from prairie dogs and their burrows from Dallam County and in pools of fleas from prairie dogs and grasshopper mice in Hartley County. Since the 1920 outbreak along the coast, there have been no proven cases of plague in Texas, although there was a suspected case in Yoakum County in March, 1950. However, New Mexico reported 6 human cases in 1949 and 1950. TULAREMIA The fact that tularemia is one of our more important disease entities transmitted, in part, by arthropods is emphasized by the 64 cases reported to the Texas State Department of Health by Texas physicians in 19 50. A majority of the cases resulted from contact with rabbits infected with the causative agent, Pasfeurella ttdarenm. Other reservoir animals include ro¬ dents, carnivores, domestic animals and game birds. In addition to contact with infected animals, human infections may be acquired by arthropod bites, particularly ticks. In Texas, the rabbit tick, Haemaphysalis leporis-palustris, and the "lone star” tick, Amblyomma ameri- canum, are incriminated as transmitting agents of Pasfeurella ftilarensis from animal to animal. Epidemiologically, A. americamim appears to be the cheif vector from the animal reservoirs to human beings, since H. le ports- palustris almost never attacks man. Sixty- three percent of the tularemia cases in 1950 occurred during April, May and June and 73 percent were contracted in the eastern half of the state. From the questionnaires sent to each physician reporting a case of tularemia, it was apparent that the disease is an occupational hazard, particularly affect¬ ing farmers, lumbermen, trappers and other workers in the field. Tularemia is frequently fatal to rabbits and rodents. In man, although the disease is debilitating and runs a tedious course, the fatality rate is low and serious sequelae seldom encountered. It appears obvious that the tularemia infection potential is sufficiently great to warrant the exercising of extreme caution in the handling of cottontail rabbits, particularly in the eastern half of the state. Gloves should be worn while skinning the animals and the flesh thoroughly cooked before it is eaten. Secondary precautions involve the use of repellents in tick-infested areas. MALARIA Malaria incidence in the United States has shown a steady decline since 193 5, until at the present time a case of locally acquired malaria is a rarity. However, in 1950 Texas physicians still reported 1,601 cases. A majority of the cases were diagnosed clinically and without the necessary laboratory con¬ firmation. Even when blood slides were made, lack of experienced technicians to examine them invalidated or rendered questionable positive findings. Only five positive malaria smears which were from cases apparently contracted in Texas were examined by personnel of this Department. Other positives seen were acquired in Mexico or other tropical countries or were induced in 124 The Texas Journal of Science 1953, No. 1 March malaria therapy directed against syphilis spirochetes in paretics. At the present time malaria is almost non-existent in Texas^ with the possible exception of the lower Rio Grande Valley, RELAPSING fever This tick borne spirochete infection characterized by alternating febrile and afebrile periods commonly known as "relapsing fever” has been of general interest in Texas since it was first reported in the state in 1927. One hundred cases of relapsing fever were confirmed by this Department by demonstration of spirochetes in thick films of the patients blood, or in blood films of rodents inoculated with a small amount of the patients blood, during the period June, 1942 through May, 1949. The cases occurred chiefly in the central part of the state, with scattered cases in all but extreme east Texas. During the same period of time, specimens of Ornlthodoros turicata have been taken in 44 Texas Counties, with a majority of the pools of ticks showing individuals harboring spirochetes. During 1950, this Department confirmed only one case of relapsing fever. Texas physicians reported 18 cases in 1950. Investigations of relapsing fever cases have indicated that the most common opportunities for infected ticks to bite man is afforded during the course of such activities as the demolition of old structures (particularly the flooring), exploring "bat” caves, crawling under houses to effect repairs or to do termite work, and overnight occupancy of hunting and fishing shacks. SUMMARY During 1950, Texas physicians and the State Department of Health reported the following cases of diseases, transmitted wholly or in part, by arthropods: dysentery-— 37,52 5 ; malaria— -1,601 ; typhus— 222; tularemia— 64; dengue— 24; relapsing fever — 18; Q fever— 4; and spotted fever— 1. ECTOPARASITES OCCURRING ON MAMMALS IN THE VICINITY OF FORT HOOD, TEXAS^ ROBERT A. HEDEEN, 1ST LT., MSC Department of Preventive Medicine Medical Field Service School Fort Sam Houston, Texas INTRODUCTION This paper is a sumary of work done by the survey section of the 498 th Preventive Medicine Company during the winter and early spring of 1952, in conjunction with the joint Army-Air Force maneuver, Exercise Longhorn. As this area, in the vicinity of Fort Hood, Texas, had not been surveyed for ectoparasites previously, it was considered advisable by the writer to make this survey for the benefit of the maneuver and any other future military operation which may take place in this area. No new species of ectoparasites were encountered, but as far as can be determined several new host records were obtained. One new locality record for the state of Texas was found. METHODS Several methods were employed to collect the mammals that were examined. Small rodents were trapped alive using a tin can-mousetrap device. Number 0 steel traps were useful for taking some of the larger mammals, and a 20-guage shotgun was most helpful in collecting rabbits and other larger forms. As soon as an animal was collected, it was placed in a bag or collecting jar and removed to the laboratory where chloroform was introduced into the container. The animal and the collecting receptacle were then placed in an enamel pan and carefully examined for the presence of ectoparasites. The combing technique was employed as was the "milking” method, as described by Hubbard (1947), to remove the ectoparasites. In many instances mites were separated from the host with a pair of fine forceps while the host was being examined under the dissecting microscope. Parasites that were not to be examined immediately were stored in vials containing 70% alcohol with a drop of glycerine added. Fleas and mites were first cleared in sodium hydrox¬ ide and then mounted on slides for identification. Ticks were identified under the dissecting microscope, and sucking lice were examined with compound and dissecting microscopes. MEDICAL IMPORTANCE OF THE ECTOPARASITES COLLECTED Several species of ectoparasites encountered have been incriminated in disease transmission. Their presence in this area would be of considerable epi¬ demiological significance in the event that any of the diseases with which they are associated should occur. Existing conditions made it impossible to 1 The author is indebted to Lt. Col. Robert Traub, MSC Chief, Department of Entomology, Army Medical Service Graduate School, for determining some of the fleas, and for his helpful advice. 125 126 The Texas Journal of Science 1953, No. 1 March determine in the laboratory if any of the ectoparasites collected were infected with disease organisms. The following medically important species were collected: Vectors of Endemic Typhus Fever. The following fleas collected in this survey have been found by other workers to be capable of transmitting endemic typhus fever: Xenopsylla cheopis; Ctenocephalides felis; Pulex ir- ritans; Echidnophaga gallinacea. In addition, the sucking louse Polyplax spimilosa and the mite Bdellonyssus bacoti, which have been long suspected as playing an important role in the transmission of the typhus rickettsiae from rodent to rodent, were collected in fairly large numbers. Vectors and Rodent Reservoirs of Plagtie. Wayson (1947) lists twenty- five species of fleas which are proven vectors of sylvatic plague in the western United States. Four of these which were collected in this survey are Cteno¬ cephalides felis, Orchopeas sexdentatns, Pulex irritans, and Xenopsylla cheo¬ pis. The following genera of mammals were examined in this survey and are listed by Wayson as having been found to be either infected with sylvatic plague or harboring plague-infected fleas: Dipodomys; Peromyscus; Sigmo- don. Sylvatic plague has been found to occur in Dawson, Cochran, Gaines, and Yoakum counties in the state of Texas. The fleas Echidnophaga gallinacea ^ndOrchopeas sexdentatns which were collected during this survey have been found naturally infected with the plague bacillus in Texas (Eads, 1950). None of the mammals, however, from which plague-infected tissue was taken in western Texas were collected in this area. Vectors of Helminthic Diseases. The fleas Ctenocephalides felis and Pulex irritans, which serve as both the intermediate host and transmitting agent of the common tapeworm, Dipylidum caninum, were, as stated before, collected in large numbers from a variety of hosts. Vectors of Tularemia. The so-called rabbit tick, Haemaphysalis leporis- palustris, which plays an important part in the perpetuation of this disease in nature, was found to be abundant on all rabbits examined. Amblyomma americanum, the lone star tick, which is also a suspected vector of "Bullis fever”, was collected frequently from a large number of hosts, including man. HOST INDEX Parasites listed in order of abundance within each group. CLASS MAMMALIA ORDER CARNIVORA ( 1 ) Procyon lotor fuscipes — Texas raccoon. Two examined. SIPHONAPTERA Pulex irritans L. Ctenocephalides felis (Bouche) (2) Canis familiaris L. — Domestic dog. Eleven examined, SIPHONAPTERA ACARINA Pulex hr tans L. Amblyomma americanum L. Ctenocephalides felis (Bouche) Dermacentor variablis (Say) Echidno phaga gallinacea (Westwood) 1953, No. 1 March Ectoparasites on Mammals 127 (3) Felis domestica L. — -Domestic cat. Seven examined. SIPHONAPTERA Ctenoccphalides felis (Bouche) Piilex irritans L. Echidna phaga gallinacea (Westwood) (4) Mephitis vicsomelas mcsomelas Lichtenstein — Striped skunk. Three examined. SIPHONAPTERA ACARINA Puiex irritans L. Ixodes sp. Orchopeas sexdentatus (Baker) Ainblyomina americanum L. ANOPLURA Haematopinus sp. (5) Perognathus hispidtis Baird-Pocket mouse. Three examined. SIPHONAPTERA ACARINA Orchopeas leucopus (Baker) Androiaelaps sp. (6) Perognathus inerriami Allen-Pocket mouse. Two examined. SIPHONAPTERA Orchopeas leucopus (Baker) (7) Baiomys taylori (Thomas) — Taylor’s field mouse. Fifteen examined. SIPHONAPTERA ACARINA Jellisonia ironsi (Eads) Bdellonyssus bacoti (Hirst) Orchopeas leucopnis (Baker) Echidnophaga gallinacea (Westwood) (8) Dipodornys elator Merriam-Kangaroo rat. One examined. SIPHONAPTERA Mcringis arachis (Jordan) (9) Peromyscus leucopus texanus (Woodhousc) — White-footed mouse. Eight examined. SIPHONAPTERA ACARINA Orchopeas leucopus (Baker) Bdellonyssus bacoti (Hirst) Meringis par her i Jordan Jellisonia ironsi (Eads) (10) Peromyscus boylii (Baird) — Rock mouse. Nine examined. SIPHONAPTERA ACARINA Orchopeas leucopus (Baker) Bdellonysstis bacoti (Hirst) Atyphloceras echis Jordan and Echinolaelaps echidninus (Berlese) Rothschild (11) Peromyscus pectoralis Osgood — Acorn mouse. Nineteen examined. SIPHONAPTERA ACARINA Orchopeas leucopus (Baker) Bdellonyssus bacoti (Hirst) 128 The Texas Journal of Science 1953, No. 1 March (12) Peromyscus manlculatus (Wagner) — White-footed mouse. Twelve examined. SIPHONAPTERA ACARINA Orchopeas leticopns (Baker) Bdellonysstis bacoti (Hirst) Meringis parkeri (Jordan) (13) Sigmodon hispidiis (Audubon and Bachman) — Cotton rat. Two examined. SIPHONAPTERA Ecbtdnophaga gallinacea (Westwood) (14) Mils tmisculus L. — House mouse. Forty-five examined. SIPHONAPTERA ACARINA Xenopsyila cheopis (Rothschild) Bdellonysstis bacoti (Hirst Echidnophaga gallinacea (Westwood) Laelaps nut t alia (Hirst) ANOPLURA Polyplax spinulosa (Burmeister) ORDER LAGOMORPHA (15) Lepus californicns Gray-Black-tailed jackrabbit. Eleven examined. SIPHONAPTERA ACARINA Pulex irritans L. Hoplopsyllus af finis (Baker) Polyplax spiniilosHS (Burmeister) Haemaphysalis leponis palustris (Packard) (16) Sylvilagus florid anus (Allen) — Cotton rabbit. Four examined. SIPHONAPTERA ACARINA Hoplopsyllus affinis (Baker) Haemaphysalis leporis palustris Cediopsylla simplex (Baker) (Packard) ORDER XENARTHRA (17) Dasypus novemcinctus texanus (Bailey) — Texas armadillo. One ex¬ amined. ACARINA Amblyomma americanus L. ORDER ARTIODACTYLA (18) Bos taurus L. — Domestic cow. Twelve examined. SIPHONAPTERA ACARINA Pulex irritans L. Amblyomma americanum L. Otobius megnini (Duges) (19) S#/5 scrofa L. — Domestic hog. Eight examined. SIPHONAPTERA ACARINA Pulex irritans L. Amblyomma americanum L. ANOPLURA Haematopinus suis L. 1963, No. 1 March Ectoparasites on Mammals 129 (20) Ovh arks L,— Domestic sheep. Five examined, diptera Meiophagtis ovinus L. (21) Myoiis velifer (Allen)— Cave Bat. Ten examined. diptera acarina Trichobim major Coquillet Chiroptonyssns robustipes (Ewing) NEW flea host records Based on Eads (1950)^ the following appear to represent new flea host records for the State of Texas; Perognathus merrami (Allen) Baiomys taylori (Thomas) Dipodomys elator (Merriam) Peromyscus leucopus texamis ( Woodhouse) Peromyscus boylii (Baird) Peromyscus pec tor alls (Osgood) Peromyscus maniculatus (Wagner) NEW FLEA RECORD FOR TEXAS As far as can be determined no member of the genus Atyphloceras has been reported to occur in the state of Texas. One specimen of A, echis Jordan and Rothschild was collected from Peromyscus boylii (Baird) . SUMMARY A survey of the ectoparasites of various mammals in the vicinity of Fort Hood, Coryell County, Texas, was made by the survey section of the 498th Preventive Medicine Company during the winter and early spring of 1952. Two hundred mammals representing twenty-one species were ex¬ amined during the course of this investigation. Twelve species of fleas, five species of ticks, six different mites, three types of sucking lice, and two species of parasitic diptera are listed from this area. New host and locality records are given and the species of ectoparasites of medical im¬ portance are pointed out. LITERATURE CITED Eads, Richard B.~1950 — The Pleas of Texas ^ Texas State Health Department, Austin, Texas. Hubbard, C. Andressen — -1947 — The Pleas of Vf^estern North America, The Iowa State College Press, Ames, Iowa. Wayson, N. P—\9An —Plague Field Surveys in Western United States During Ten Years (1936-1945), Public Health Reports 62: 780-791. Ore ho peas leucopus (Baker) Orchopeas leucopus (Baker) Enchidnophaga gallinacea (Westwood) Meringis arackis (Jordan) Echidnophaga gallinaces (Westwood) Orchopeas leucoptis (Baker) Orchopeas leucoptis (Baker) Ore ho peas leiico pus ( Baker ) Meringis pakeri (Jordan) FERTILITY STATUS OF CULTIVATED SOILS IN WICHITA COUNTY, TEXAS WILLIAM O. TROGDON Midwestern University During periods of national emergencies agriculture is called upon for increased production. In the past, farmers have assumed the responsibility for success in meeting the challenge to agricultural production by expand¬ ing acreage, making more use of mechanized equipment and using improved production methods. Just as the great but absolutely necessary shift from the highly wasteful farming practiced during the years of World War II was on, another international crisis confronted us and the farmer was again called upon for increased production. Immediate increased production does not usually allow an operator to follow a long-time plan. He must respond with more production of the critical crops, usually clean-tilled ones — cotton, corn, grain sorghums, vegetables and other products needed for human and animal consumption and for defense manufacturing. This, together with the shortage which defense creates in the fertilizer output, generally postpones programs designed to maintain and improve the fer¬ tility of the soil. Farmers and ranchers in Wichita County are vitally concerned with increasing per acre yields by making full use of improved production meth¬ ods and at the same time rebuilding soils of the area to a higher state of productivity and stopping the decline in soil fertility. Field inspections, both from the ground and from the air, furnish sufficient proof that maximum productivity is not being obtained from many acres of farm land due to erosion, poor physical condition of the soil, lack of fertility and failure to use improved production methods. While high productivity is the over-all result of many things (3,6)^, such as good weather, a good supply of necessary elements, good seeds, good farm¬ ing methods and a soil that has good physical properties, very little infor¬ mation is available to accurately determine the factor or factors limiting production. Lack of moisture, except for the irrigated area, often renders farming operations unsatisfactory, but even during seasons of good weather many farmers are not able to obtain high productivity. This study of the fertility status of cultivated soils in Wichita County was made to determine whether higher production could be obtained from increased soil fertility or whether other factors were complicating produc¬ tivity. Farmers need such information in order to obtain the most economi¬ cal returns from the use of fertilizers and other improved production methods. CLIMATE AND SOILS Wichita County is located in the extreme northern part of Texas on the eastern edge of the Rolling Plains region. The county is almost equi¬ distant from the eastern and western sides of the State. 1 Figures in parenthesis refer to "Literature Cited’’. 130 1963, No, 1 March Fertility Status of Cultivated Soils 131 The climate is temperate, subhumid and rather variable (2). The wide variation in rainfall, ranging from about 15 to 47 inches, with May-June and September-October being the wetter months, has resulted in the devel¬ opment of soils whose physical characteristics resemble those of both the humid and semiarid regions, but whose dominant characteristics are more like those of the semiarid soils ( 1 ) . Carter et al ( 1 ) found the "Red Beds” clays, with associated inter- bedded sandstones, mudstones, and clay shale layers, to have given rise to the largest areas of soil in the county. The sedimentary soils are largely de¬ posits of materials washed from the "Red Beds” areas. The three broad groups of soils in the county are the dark colored soils, the red soils and the brownish red soils. In these groups are nine soil series, which include 2 5 soil types and 5 phases. PROCEDURES AND METHODS In this study 322 topsoil and 290 subsoil samples from 5 5 irrigated and 6 5 non-irrigated farms, representing all the soil series in the county, were analyzed. These farms represent 10 percent of the farms in Wichita County. The soil samples, with the exception of the subsoil samples which were not analyzed for organic matter content, were analyzed for easily oxidizable organic matter, easily soluble phosphorus, exchangeable and soluble potassium, calcium and sodium. pH and specific conductivity were also determined on each sample. Soil samples were air dried and crushed to pass a sieve with 2 milli¬ meter openings. pH and specific conductivity were determined on a 1:2 soil-water ratio, using a glass electrode and a Sol-U-Bridge soil tester. Or¬ ganic matter was determined by the modified Walkley and Black method as outlined by Peech et al (4). For easily soluble phosphorus 5 grams of soil were extracted with 100 cc of O.lN acetic acid for 3 0 minutes with the phosphorus being determined on aliquots of the filtered supernatant liquid by the method of Truog (7). Soluble and exchangeable calcium, po¬ tassium and sodium leached and displaced from the soil with 1 : 5 ratio of neutral normal ammonium acetate ( 5 ) were determined by the direct in¬ tensity method using a Perkin-Elmer Flame Photometer. DISCUSSION AND RESULTS The fertility levels or adjective ratings used in this study correspond closely with those used by the Soil Conservation Service Regional Operational laboratory and the soils laboratory at Texas A & M College. For maximum productivity of most crops, if climatic conditions are suitable, the fertility rating should be medium or higher. In this study sodium is used as an indication of poor physical conditions rather than as a plant nutrient and the lower the sodium content the better. Unpublished data by the author indicate that when the calcium: sodium ratio in these soils is less than 20:1 poor physical condition of the soil, due in part to dispersion of the colloidal clay, tends to limit yields more than the fertility level. Table 1 shows the number of topsoil and subsoil samples in each rating. Table 2 gives the percentages of topsoil and subsoil samples for each rating. TABLE I 132 The Texas Journal of Science 1953, No. 1 March Uh o c/5 1-1 < w H oc c^ ON 'o xr CN ' I— < T— I rn r-' VD CO o (^1 rOi rvl (^1 o >H CQ Q w H . < CO Q S S 2 o CO CN O r- O c- 'T CO 1^ o r^i rr-. r-j o cv) r\| CN lo O) m VD f'' — < r\| rsj XT VO 'O m ro r^i m CN ‘UD 3 3 lo cs VD r^i r-i VD ir\ rr, r-l r-^ Pi 'o CL O O cc ^ r\ cc rr CN r— I >0 rO. lO \o 0\ C\ ^ ^ ^ r\i m I c e d (U a o c'J qj -3 j3 ^ .'H '3 ^ Exchangeable and soluble in neutral normal ammonium acetate TABLE II 1S53, No, 1 March Fertility Status of Cultivated Soils 133 p w ‘o c\ l/N * q CO m CM m H n rn NO rn rn d d NO NO < C3 rOi 'T \r\ U 6 " S g O CO ‘o ITN q (N Os q P q Z-i Cl. c\ P P P 00 d 00 C/D o m I — 1 un m 'T w CO > W < Pm H O CM O CM 'T q q 00 P O CM o e d d P ir\ CM n- On ON H q d d w S u w o u CO Pm D g CO W '3 O ON d q d l/N 6.2 wn rn 00 00 m 00 S < &M < ft o m m ON p-i CO o hJ CO < o CO m p 'c ON Oj q q 'T q rn X ftl d l/N d P 00 P d m rn n) 00 H CO 6 X o On =3 H Csi p O P go £ s r*i ON ON rn rn q q U tl O P d d P d d P p < I— 1 'T rn On < H n4 X O C/D U o H 'o 00 "T m iq ni ao NO d CM ON P d rn d g CN CM d u, \r\ CM r-- nt m o CO Pm o _a ft c« o 6 CO CO ft o v> q rOi 'T r-- --M 00 q q p X ft oc d rn vn NO p NO d hJ O CN CM m T— < M}" H < < > < Sh OJ H W rt —I p U P H 6 ‘o c« q q rn q .y ft ON rn ni d rn P d d til X G 2 m XT On o ffl bJO Sh O w s O .2 < s. d H P O 6 6 -ft (L» > 2 w u w &o .S U o Sh SJ very Lo o o d D" "O .2 "U 4^ High >. t-i > d rt m ’H d 2 o 2 4i > p ►5 p I i I j o J 134 The Texas Journal of Science 1953, No. 1 March The most outstanding fact shown by these data is that more soils have an inadequate supply of organic matter and nitrogen, since organic matter and nitrogen are approximately proportional, than any other fertility ele¬ ment. 82.3 percent of the topsoil samples were either low or lower in organic matter and those samples in the low to medium rating should benefit either directly or indirectly from an increase in high quality organic matter, mak¬ ing a total of 94.4 percent of the soils in which increasing the organic matter content is a problem. Not only would increasing the organic matter content affect the fertility level of the other plant nutrients but also the physical properties of the soil, aeration and water relationships (3). 5 5.7 percent of the topsoil and 79.3 percent of the subsoil samples showed an inadequate supply of available phosphorus, especially for those crops with higher than average phosphorus requirements. Using phosphate fertilizers for legumes on phosphate deficient soils is now accepted by most farmers as an improved production practice. This practice, together with returning residues to the land and tillage methods, helps to account for the topsoil being better supplied with available phosphorus than the subsoil. At the present time very few soils in Wichita County are not ade¬ quately supplied with potassium and calcium. Potassium deficiency was found in only 7.1 percent of the topsoil and 18.7 percent of the subsoil samples. Only 5 topsoil samples and 1 subsoil sample were deficient in cal¬ cium. Some of our soils probably contain too much active calcium, especi¬ ally in rather severely eroded areas. The calcium: sodium ratio is a fairly good index of some physical properties that might be limiting crop production. When the ratio is narrow the clay tends to be dispersed, clogging the soil pores, impeding water move¬ ment through the profile, affecting aeration and causing severe crusting of the surface. Consequently, poor physical condition of the soil aggravated by too much sodium is likely to affect the productivity of about half of the soils in the county since 48.1 percent of the topsoil and 56.5 percent of the subsoil samples contained an overabundance of sodium. The data show that soils generally contain very low amounts of sodium or else very high amounts. There tends to be little gradation as in the case of organic matter, potassium and calcium. pH for most of the samples ranged from about 6.1 to 8.6 with the greater percentage of samples being neutral or slightly alkaline. Specific conductivity varied considerably, depending on the internal drainage con¬ dition of the soil, but tending to be higher in the more compact clays. The data obtained in this study indicate that cropping systems and practices which will increase the organic matter content of the soil and open the subsoil so that excessive sodium can be leached, together with supplemental nitrogen and phosporus fertilization to improve the quality of organic matter, are needed to raise the fertility level of cultivated soils in Wichita County for higher productivity. The use of nitrogen and phosphorus fertilizers without considering the need for cropping practices to improve the soil physical condition is apt to be disappointing unless the soil is in good physical condition. At the present time there is very little need for potash fertilization and practically no need for any extra calcium as a plant nutrient. Demon¬ strations and unpublished data obtained on many of these soils have shown extra calcium, especially as gypsum, to be a good practice in bringing about better soil structure. Gypsum, as a soil conditioner, is needed on many of 1953, No. 1 March Fertility Status of Cultivated Soils 135 the high sodium soils in order to promote flocculation and granulation, espe¬ cially where deeper rooted legume plants are used to penetrate the subsoil and improve internal drainage. SUMMARY The fertility status of cultivated soils in Wichita County, Texas, has been studied. Data are included to show the various fertility ratings of the topsoil and subsoil samples, as determined by chemical means in the laboratory. 94 percent of the topsoil samples were found to be deficient in organic matter, and probably in nitrogen, since they are approximately pro¬ portional. Over half of the topsoil samples showed a need for additional phosphorus, but very few samples indicated a need for additional potash or lime. Nearly half of the soils contained sufficient sodium to bring about poor physical condition which might limit productivity. In order to obtain higher productivity many farmers will have to adopt cropping systems that will improve the organic matter content of their soils. Using nitrogen and phosphorus fertilizers, especially for legumes and grasses that are to be returned to the soil, to raise the fertility level of the soil at the same time the physical condition is being improved, will result in increased per acre yield on many farms in Wichita County, Texas. LITERATURE CITED 1. CARTER, W. T. Strike, W. W. Geib. H. V., and Templin, E. H.— 1929— Soil survey, Wichita, County, Texas. U. S. Department of Agriculture, survey re¬ port number 19 series 1924, 2. Moore, E. A. — "1950- — Lncal climatological sum-mary luith comparative data, Wichita Falls, Texas. U. S. Department of Commerce, Weather Bureau 3. Page, J. B. and Willard, C. T. — 1946 — Cropping systems and soil properties. Soil Sci. Soc. Amer. Proc. 11:81-88. 4. Peech, M., Alexander, L. T. De-^n. L. A., and Reed, J. F. — 1947 — Methods for soil analysis for soil-fertility investigations. U. S. Dept, of Agric. Circ, No. 757. 5. Schollenberger, C. J. and Simon, R. H. — 1945 — Determination of exchange capacity and exchangeable bases in soil-ammonium acetate method. Soil Sci. 59h 13-24 illus. 6. Trogdon, W. O. — 1950 — The effect of acid and base forming nitrogenous fertilizers on certain soil factors affecting soil productivity. Abstracts of Doctoral Dissertations, Ohio State University 59:409-416. 7. Truog, E. — 1930 — The determination of the readily-available phosphorus of soils. Amer. Soc. Agron. jour. 22:874-882. The preceding issue of The Texas Journal of Science^ VoL IV, No. 4, was mailed to subscribers on January 16, 195 3. The Texas Journal of Science 1953, No. 1 March Professional Directory J. BRIAN EBY Consulting Geologist 347 Esperson Bldg. Ph, CH-4776 Houston, Tex. PETTY GEOPHYSICAL ENGINEERING COMPANY Seismic Gravity Magnetic Surveys 317 Sixth St. San Antonio, Texas LEONARD J. NEUMAN Registered Professional Engineer Geological and Geophysical Surveys Petroleum Engineering Reports Houston, Texas Geophysics Office Engineering Office 943 Mellie Esperson Bldg. Ph. Preston 2705 Ph. FA-7086 ZINGERY BLUE PRINT CO. (“Greater Distance - Greater Discount”) Phone Atwood 6483 435 Esperson Building Houston 2, Texas LEO HORVITZ Geochemical Prospecting Horvitz Research Laboratories ' Houston, Texas Ph. KE-5646 3217 Milam Street E. E. ROSAIRE Prospecting for Petroleum DALLAS, TEXAS MICHEL T. HALBOUTY Consulting Geologist and Petroleum Engineer Shell Building Houston 2, Texas Phone PR-6376 H. KLAUS Geologist KLAUS EXPLORATION COMPANY Lubbock, Texas D’ARCY M. CASHIN Geologist Engineer Specialist Gulf Coast Salt Domes Examinations, Reports, Appraisals Estimates of Reserves 2018 Nat’L Standard Bldg. Houston 2, Texas Consulting Geologists Appraisals Reservoir Engineers DeGOLYER and MacNAUGHTON Continental Building DALLAS. TEXAS WILLIAM H. SPICE, JR. Consulting Geologist 2101-03 Alamo National Building 1 SAN ANTONIO 5. TEXAS SAMPLE AND CHILDERS C. H. Sample A. F, Childers, Jr. Consulting Geologists 901 Southern Standard Bldg. Houston 2, Texas HERSHAL C. FERGUSON Consulting Geologist and Paleontologist Esperson Building HOUSTON, TEXAS 8251/2 Gravier Street New Orleans, La. JOHN L. BIBLE Tidelands Exploration Co. Seismic & Gravity Surveys on land and sea 2626 Westheimer Houston, Texas 1953, No. 1 March The Texas Journal of Science Professional Directory Continued LOCKWOOD & ANDREWS Consulting Engineers Houston S. RUSSELL (PAT) CASEY, JR. Petroleum Management Company Electric Building , Phone CH-1622 Plouston, Texas DALE SHEPHERD, C. L. U. and Associates Estate Analysis - Pension Planning Insurance Programming - Business Insur. General Agents Connecticut Mutual Life Insurance Co. 1802-3-4-5 Esperson Bldg. Houston t^'*i**i**?'**§**i**I*'*'I**'*S*'*i**i*^ *1* *1* »I* »i* GEOCHEMICAL SURVEYS 3806 Cedar Springs Rd. Dallas 4, Texas & 318 F&M Bank Bldg. Abilene, Texas For DELIGHTFUL VACATIONING ... SWIMMING . . . BOATING . . . FISHING ... OR JUST LOAFING . . . NEW . . . MODERN . . . REFRIGERATED AIR CONDITIONING COTTAGES OF CEDAR CONSTRUCTION ELECTRIC KITCHENS OVERLOOKING LAKE BUCHANAN SHOWERS SCREENED PORCHES STEEL BOAT WITH EACH CABIN BLUEBONNET REST RANCH 70 MILES NORTHWEST OF AUSTIN BUCHANAN DAM, TEXAS TELEPHONE 2961 COL. AND MRS. HUGH E. KILLIN The Texas Journal of Science 1953, No. 1 March C. H. Broussard, Vice President of Independent, started out as a helper for IX I5V2 years ago after attend¬ ing LSU and Georgia Tech. He has progressed through every job in the exploration field including computer, party chief, review department head, and chief geophysicist. He has a total of 17 years experience in geophysical work. Experience, Equipment and Modern T echniques are the keys to your Expioration Success Independent Exploration Company has contributed generously to the development of new equipment and modern techniques during the 20 years in which it has served the oil industry. Now one of the oldest and most experienced explora¬ tion contractors in the business, Independent believes that experienced Party Chiefs hold a key to your exploration success. Independent’s crews under the su¬ pervision of Party Chiefs with an average of 16 years service, have served more than 100 important oil producers. Me^Utl ^044^ Go44.^ulle4t7Ce> Independent Qe»f}Ui^A4caL EXPLORATION COMPANY 1973 WEST GRAY HOUSTON, TEXAS I I S H £ D 19 3 2 A MAN MA5 T’^N 'FfNGER5 ano one ! 5CMi.OMSE'RGER. Ma5 ONE MAN IN I^ESEARCM F-OR EVERy 'Ten MEN I n'T^-^E EfE£,0 / WM/' O^ERAToR5 5 cmeumb^ir.g^r.=i ScMumberger Weli Surveying Corp. # Houston, Texos 1953, No. 1 March The Texas Journal of Science RARE FOORS W I N E S , LI Q U E 11 R S AN D C HAM P A G N E S A From the World’s Markets! ^ HOUSTON, TEXAS As courtesy to the Academy, in doing business with our advertisers, please make mention of the fact that you saw their advertisement in THE TEXAS JOURNAL OF SCIENCE. MISSION Super-Surface LINERS with SATIN FINISH MISSION Super-Service SLUSH PUMP VALVE for the smallest or the largest mud pump ^Ussion manufactures a complete line of parts MISSION Fluid end PISTON with MISSION Super-Surfaced PISTON ROD MISSION Self-Sealing GLAND PACKING -A > PUBLISHED PARTIRLY byTHE TEXAS ACADEMY OF SC1EN£E ' JUL1GIC53-' For twenty-one years, SEl has specialized in sub-surface studies of the domestic oil provinces . from Canada to the Gulf. Numerous innovations in instrumentation, inter¬ pretation, and field technique have kept SEl in the fore¬ front. For example, in difficult areas, SEl has been a pioneer in the use of patterns of multiple shot holes and geophone arrays Your exploration program is in capable hands at SEl. lEIIMK EXPLORATIONS INCORPORATED 1D07 SOUTH SHEPHERD HOUSTON, TEXAS your guarantee of Extra quality HUMBLE MOTOR FUEL * £sso Uniflo Csso Extra OASoitNE & motor oil ATLAS TIRES & BATTERIES RESfE^mRCH THAX MEWER EMDli WeVe never made a rock bit that completely satisfied us . . . and we never will, although we have made millions of bits. One improvement has invariably led to others, opening new frontiers for research and progress. As a result, record breaking bits of not too many years ago have become today’s museum pieces. Through the years Hughes Tool Company’s expenditures in research and engineering to improve the performance of its bits and advance rotary drilling have run into millions of dollars. Currently, these expenditures are at a rate of more than $ 1 ,500,000 per year. This continuing research enables Hughes to keep pace with the constantly changing needs of a fast moving drilling industry. Progress dictates that we can never be satisfied with any improvement of the moment. EXECUTIVE COUNCIL, 1953 President: D. B. Calvin, The University of Texas, Medical Branch Executive Vice President: Joseph P. Elarris, Jr., Southern Methodist University Secretary-Treasurer: Gladys H. Baird, Huntsville Representative to A. A. A. S. : C. M. Pomerat, The University of Texas, Medical Branch Vice President, Sec. I, Physical Sciences: D. F. Leipper, The A. & M. College of Texas Vice President, Sec. II, Biological Sciences: E. L. Miller, Stephen F. Austin State College Vice President, Sec. Ill, Social Sciences: Edith L. Robinson, Texas State College for Women Vice President, Sec. IV, Earth Sciences: S. E. Clabaugh, The University of Texas Vice President, Sec. V, Conservation: R. P. Wagner, The University of Texas Collegiate Academy: Sister Joseph Marie Armer, Incarnate Word College Junior Academy: Greta Oppe, Ball High School, Galveston BOARD OF DIRECTORS President: D. B. Calvin, The University of Texas, Medical Branch Executive Vice President: Joseph P. Harris, Jr., Southern Methodist University Secretary-Treasurer: Gladys H. Baird, Huntsville Immediate Past President: Willis G. Hewatt, Texas Christian University Elected Director: Don O. Baird, Sam Houston State Teachers College Elected Director: E. E. Rosaire, Consulting Geophysicist, Dallas Elected Director: W. R. Woolrich, The University of Texas BOARD OF DEVELOPMENT W. R. Woolrich, The University of Texas L. W. Blau, Humble Oil & Refining Company, Houston Everette DeGolyer, DeGolyer and McNaughton, Dallas J. Brian Eby, Consulting Geologist, Houston O. S. Petty, Petty Geophysical Company, San Antonio Allan Shivers, Governor of Texas MEMBERSHIP COMMITTEE Chairman: E. L. Miller, Stephen F. Austin State Teachers College CONSERVATION COUNCIL President: John G. Sinclair, The University of Texas, Medical Branch PURPOSE : To encourage and coordinate research in Texas by bringing scientific workers together and by publishing the results of their investigaticn£, : to advise individuals and the government on scientific matters ; to assemble and maintain library and museum facilities. ORGANIZATION ; The activities of the Academy embrace all scientific fields. In the Senior Academy, there are five Sections : Physical. Biological, Social, and Geological Sciences, and Conservation. Regionally, the Senior Academy is divided into three branches : East Texas, South Texas and West Texas. The Collegiate Academy promotes the organization of science clubs in colleges and universities. The Junior Academy encourages scientific activities in secondary schools. MEMBERSHIP; “Any person engaged in scientific work, or interested in the promotion of science” is eligible to membership. PUBLICATIONS; The Proceedings and Transactions of the Academy are incorporated in THE' TEXAS JOURNAL OF SCIENCE, published quarterly. MEETINGS; State-wide annual meetings are held in the fall, and regional meetings in the spring of each year. DUES; Annual members, $5 per year. Life members, at least $100.00 in one payment. Sustaining Members, $10 per year. Patrons, at least $500.00 in one payment. Life members and patrons are exempt from dues, receive all publications, and participate as active members. SUBSCRIPTION RATES; Members $5 per year. Single copies $1.25 each. Volume V, No. 2, June, 1953 Published Quarterly at San Marcos, Texas (Entered as Second Class Matter, at Postoffice, San Marcos, Texas, M'arch 21, 1949) Tke Texas J ournal of Science Published Quarterly by The Texas Academy of Science EDITOR T, N. Campbeli Department of Anthropology The University of Texas Austin, Texas ASSOCIATE EDITORS John W. Forsyth Department of Biology Texas Christian University Fort Worth, Texas Claude C. Albritton, Jr. Department of Geology Southern Methodist University Dallas, Texas Guy T. McBride, Jr. Department of Chemistry The Rice Institute Houston, Texas John G. Sinclair Department of Anatomy The University of Texas Medical Branch Galveston, Texas J. Brian Eby, Chairman John J. Andujar . Anton Berkman . L. W. Blau. . C. C. Doak. . . John C. Godbey. ..... Joseph P. Harris, Jr. . . . . W. G. Hewatt . H. A. Hodges . Clifford B. Jones . Ernest L. Kurth . . John B. Loefer. ....... K L. Miller . . . . C. M. Pomerat . E. E. Rosaire. .... . . . . H. J. Sawin. ......... Aaron P. Seamster. . . . . C. M. Shigley . Cornelia Smith . . . Victor J. Smith. ...... Otto O. Watts ....... Arthur W. Young . PUBLICATION BOARD . . . . . . Consulting Geologist, Houston . Fort Worth Medical Laboratory . . Texas Western College . Humble Oil & Refining Co., Houston . The A. & M. College of Texas . . Southwestern University . Southern Methodist University . Texas Christian University . Pan American College . Texas Technological College . Southland Paper Mills, Inc., Lufkin .... Southwest Foundation for Research and Education . Stephen F. Austin State College . The University of Texas, Medical Branch . Consulting Geophysicist, Dallas . . . . . .University of Houston . . . . Del Mar College . . Dow Chemical Company, Freeport . Baylor University . . . . . . . . Sul Ross College . . Hardin-Simmons University . . . Texas Technological College ADVERTISING DIRECTOR Robert Lee Miller & Associates 1951 Richmond Houston 6, Texas Volume V No. 2 COVER PICTURE This picture provides a dramatic contrast between the old and the new in South Texas livestock. The Longhorn, which weighs about 2,000 pounds and stands head and shoulders above the surrounding Zebu, was raised from a calf by Mr. Henderson Coquat on his Cantarana Ranch in La Salle County. Now about eleven years old, this giant moves with a herd of fine Zebu cattle, over which he is absolute boss. As he has the wari¬ ness or the old-time Texas Longhorns, the photograph had to be taken from the back end of a feed truck. Photo by Glen L. Evans. Courtesy of the Teaxs Memorial Museum. Tke Texag J ournal oi Science CONTENTS FOR JUNE, 1953 The Development of Ecology and Its Relationship to Paleontology, Gordon Gunter . . . . . 137 Radioactive Isotopes as Tracers of Antibodies. Ludwik Anigstein . . 148 Hyalite (Fluorescent Opal) from Llaoo County, Texas. Robert M. Hutchinson . . . 154 The Ecological Distribution of the Birds of the Black Gap Area, Brewster County, Texas. William Lay Thompson . . . 158 Culture Change as Revealed in Cochiti Pueblo Hunting Customs. Charles H. Lange . . . . . . . . 178 Forced Bending Vibration of Nonuniform Beams with Periodic Excitation. Robert B. Grant and James G. Steward . . . . 185 The Motion of a Rigid Body with Nonholonomic Constraint. William P. Mmden, Jr. . . . . . . 192 Operational Analysis of Nonlinear Systems. Robert B. Grant ................ 198 Fish Poisoning on the Rio Huallaga, Peru. Edwin Doran, Jr. .............. 204 The Fishes of the Upper Guadalupe River, Texas. Clark Huhhs, Robert A. Kuehne, and Jack C. Ball .................... 216 Introduced Fish Species of the Guadalupe River Basin. William H. Brown . 245 A New Minnow, Notropis bairdi buccula, from the Brazos River, Texas. Frank B. Cross . . . 252 On the Uptake of Organic Iodine Compounds by the Kidneys of Some Marine Fishes. P. K. Knoefel, Jane Telford, and C. A. Handley . . . 260 Leptoderma springeri, A New Alepocephalid Fish from the Gulf of Mexico. Giles W, Mead and James Bohlke . . . . . 265 Notes on the Possible Intergradation between the Colubrine Snakes, Arizona elegans blanchardi Klauber and Arizona elegans elegans Kennicott, in Texas. Don Hunsaker II and Don Sellers . . . . 268 Science Activities in Texas 270 THE DEVELOPMENT OF ECOLOGY AND ITS RELATIONSHIP TO PALEONTOLOGY GORDON GUNTER Institute of Marine Science The University of Texas Ecology, encompassing as it does all phenomena of life in nature, is complicated and is not yet as crystallized as the other biological sciences. There is some disagreement over the importance of various observed phe¬ nomena and about the basic philosophy of the subject, especially on how ecology should be studied or approached. Ecologists are agreed that they are concerned with the relationships of organisms to* the total environment, but their books and papers show that after starting from this common point they ' travel quite different paths. This is clearly shown by a comparison of the major textbooks in English cited at the end of this paper. HISTORY AND DEVELOPMENT OF ECOLOGY As a definitive science ecology is rather young and it was less than fifty years ago that common agreement about the name was reached. Never¬ theless, its roots are old and, as Elton (1927) has stated, it is simply scien¬ tific natural history. In the broad sense man has studied and observed natural history from its beginning, with little attempt to record or analyze the facts. With the growth of science naturalists begin to weigh and measure, to observe with a purpose, to analyze and concoct theories about the thin blanket of life on the earth and to study it quantitatively in nature. Then natural history passed from what Lankester ( 1889) termed the lore of the farmer to the status of a science. Since it is scarcely possible to treat of an organism to any considerable extent without discussing its relations tO’ the environment, many of the older naturalists were good ecologists, although they may never have heard the term. One cannot read the works of Darwin, Wallace, Semper, Bates and certain others without being impressed with their grasp of what is now called ecology. Probably their primary concern with evolution prevented more extensive exposition of their ecological conceptions. Wheeler (1902) in refutation of the assertion that zoologists had neglected the field of ecol¬ ogy, which he called ethology, named fifty-one workers who^ had contributed to the field in various ways. This point is of some importance tO' the his¬ tory of the subject because some ecologists seem to think the science and its major concepts sprang full-blown in their own heads. To the contrary, the subject has developed slowly and many of the earlier biologists showed in their writings a progressive appreciation of it. We can agree with Elton that ecology was developed into a science by the brilliant naturalists before and at the time of Charles Darwin. The French savant, Buffon (1749-1804) opposed mere exposition of morphology and devoted his natural history of animals tO' consideration of their habits and adaptations to their environments. Saint-Hilaire (1859) proposed the word ethology for "the external vital manifestations of or- 137 138 The Texas Journal of Science 1953, No. 2 June ganisms,” and spoke of ethological laws. He died before writing the fourth volume of his work, in which he intended to treat the subject. Haeckel (1869, p, 3 53 ) proposed the term "oekologie” for "the relations of the animal to its organic as well as to its inorganic environment.” He first used the word in 1866 in his Generelle Morphologie der Organismen. Had Haeckel included the flora in his definition it would have been complete. Several early marine biologists became interested in zonation of organ¬ isms along the shores and the shallow sea. The writings of some were over¬ looked because of poor dissemination and they had little influence, while others were widely read. Zonation divisions set up by Audouin and Milne Edwards in 1803 were, according to Gislen (1930), quoted with "touch¬ ing constancy in France” for fifty years. M. Sars in 183 5 studied zonation in Norway. At this time various botanists described the marine algal zones. Edward Forbes (1844) did the first influential work on marine zonation in England and discussed marine biology from the ecological view. No history of marine ecology, even a brief one, is complete without mention of the works of that strange genius, Philip Gosse ( 18 53 ), who greatly forwarded the study of marine biology. His tide pool studies and discussions of littoral biology had a strong ecological bent. In spite of these beginnings, the discoveries of Darwin and the general evolution ferment of the times had the effect of confining most biologists to their laboratories, where work was largely morphological and physio¬ logical. Herdman (1896) thought it "remarkable” that the impetus given by Darwin’s work to biological investigation was chiefly directed to prob¬ lems of structure and development and not so much to field studies. He noted, however, that interest was turning to "bionomics,” as a result of concern with variation, which also stemmed from Darwin’s work, and the desire of biologists to study it in nature. He also drew attention to the relation of bionomics, as he called ecology, to fisheries and oceanography. In this connection the work of Verrill (1873) on the invertebrate fauna of Vineyard Sound is particularly worthy of note. He listed all species he could find from the various types of marine environments in that region, discussed their habits and distributions in relation to the physical environ¬ ment and also gave their known distribution in geological horizons. The nine aims, listed in his introduction, "all more or less connected with the investigations of the fisheries,” show a broad ecological viewpoint. His work was a hallmark in general marine biology and is still a valuable reference. While working on oyster reefs in the North Sea, M5bius (1877) first rec¬ ognized and defined an organic community or biocenose. At this time Forel in Switzerland was founding the science in limnology. Henson in 1887 first studied the marine plankton quantitatively. The Challenger Expe¬ dition raised many ecological questions and stimulated thought in that di¬ rection. S. H. Forbes working in fresh water fisheries and economic zoology in Illinois, expounded the ecological point of view. The botanists, Grisebach, Warming, Schimper and others (see Clements, 1905) were developing the ideas of plant associations and communities, between 183 8 and 1898. It may be said that in zoology until around 1900 the science of ecology de¬ veloped and grew more as a handmaiden to oceanography and fisheries, espe¬ cially the latter, than as a study or subject of its own. At that time a new view began to be manifested and interest in ecology and its principles per se came into vogue. Burdon-Sanderson (1893), in his presidential address 1953, No. 2 June Ecology and Paleontology 139 before the British Association, clearly expressed the matter and described the relations of the "new” science to the others in the following remarks: Now the first thing that strikes us in beginning to think about the activities of an organism is that they are naturally distinguishable into two kinds, according as we consider the action of the whole organism in its relation to the external world or to other organisms, or the action of the parts or organs in their relation to each other. The distinction to which we are thus led between the mternal and external relation of plants and animals has of course always existed, but has only lately come into such prominence that it divides biologists more or less completely into two camps — on the one hand those who make it their aim to investigate the actions of the organism and its parts by the accepted methods of physics and chemistry, carrying this investigation as far as the conditions under which each process manifests itself will permit; on the other, those who interest themselves rather in considering the place which each organism occupies, and the part which it plays in the economy of nature. It is apparent that the two lines of inquiry, although they equally relate to what the organism does, rather than to whar it ts, and therefore both have equal right to be included in the one great science of life, or biology, yet lead in directions which are scarcely even parallel. So marked, indeed, is the distinction, that Professor Haeckel some twenty years ago proposed separate study of the organisms with reference to their place in nature under the designation of 'oecology,’ defining it as comprising 'the relations of the animal to its organic as well as to its inorganic environment, particularly its friendly or hostile relations to those animals or plants with which it comes into direct contact.’ Whether this term expresses it or not, the dis¬ tinction is a fundamental one. The two branches have this in common, that both studies fix their attention not on stuffed animals, butterflies in cases, or even microscopial sections of the animal or plant body — -all of which relate to the framework of life — -but on life itself. Brooks (1899) said, "The physical sciences deal with the external world, and in the laboratory we study the structure and activities of or¬ ganisms by very similar methods; but if we stop there, neglecting the rela¬ tion of the living being to its environment, our study is not biology or the science of life.” Brooks strongly championed the ecological point of view, although he did not call it that, and indicated in one of his lectures that the biological laboratory which leaves out the outside world is "a monstrous absurdity.” He also pointed out that the greatest scientific generalization of his day (the law of evolution) was reached independently by two men "who were eminent in their familiarity with living things in their homes.” There was some discussion at this time, both in America and Europe, about the proper term for the new science which was developing in the biological field. Ecology was originally called bionomy or bionomics by many workers. In Germany it was also known as Biologic until around 1900. Those interested in the growth of conceptions concerning ecology should consult W. M. Wheeler (1902), the famous insect sociologist, who became interested in the subject and argued for adoption of Saint-Hilaire’s name, ethology. His argument on etymological and other grounds was good. Nevertheless Haeckel’s ecology finally won the day, doubtless because its proponents, chiefly the botanists in the beginning, were farther ahead with plant ecology, did more ecological work and used their term more often. Several definitions of ecology have been given. Those of Saint-Hilaire, Haeckel and Elton have been mentioned. Adams (1913) stated that ecology is concerned with the responses of organisms to their complete environ¬ ments. Shelf ord (1913) said, "The study of organisms in relation to environ¬ ment is entitled ecology. The definition of ecology, like that of any grow- 140 The Texas Journal of Science 1953, No. 2 June ing science, is a thing to be modified as the science itself is modified, crystal¬ lized, and limited. At present, ecology is that branch of general physiology, which deals tvith the organism as a whole, with its general life processes, as distingjiished from the more special physiology of organs and which also considers the organism with particular reference to its usual environment.” Pearse (1939) said, "Ecology is the branch of biological science that deals with relations of organisms and environments. It is concerned with re¬ sponses of whole organisms, or groups of organisms, to environmental stimuli, and with changes in environments brought about by activities of organisms.” Clements and Shelford (1939) said, "Ecology is in large measure the science of community populations.” It is difficult to improve upon these definitions. Probably the one given by Adams is the most succinct and inclusive. One thing in particu¬ lar deserves emphasis. Ecology is closely related to physiology in that both are studies of life or dynamic phenomena. One considers the organism as a unit dynamic system with laws of its own internal operation as a proto¬ plasmic or living system; the other considers the organisms as a unit with¬ in a larger system, where the phenomena and laws of operation and reaction are of a different order and rank. The physiologist may work without much attention to ecology and in many respects his job is simpler, but ecologists can not work their field without attention to physiology. Neither field is far enongh advanced for physiology to tell what an organism or group of organisms will do in nature, but it certainly defines the limits of what they can do. Shelford (1929) has pointed out that one of the great difficulties of ecology is the fact that the physiology of the organisms studied is little known. Another difficulty and a very complex one is the fact that in ecol¬ ogy to some extent the whole world is the stage and this environment is incompletely known and understood. The problem of the ecologist is to sift the information of physiology on one hand, and of the environment on the other, and use it to describe and elucidate the laws of life on the earth. The complexity of the task has led to a mental struggle for unity of view, to much philosophizing about ecology, and also to a concentra¬ tion upon certain aspects of the problem with over-emphasis of individual interests. Interest in ecology and its principles per se first arose at the beginning of this century largely as a result of the studies of plant communities by Warming (1909 and earlier) in Denmark and Clements (1905) in this country. They were quickly followed by Shelford (1913) from the zoologi¬ cal side, who has contributed extensively to the study of animal communi¬ ties in North America. Clements and Shelford have probably been more active than any other workers as exponents of the subject of ecology for its sake, but always with heavy emphasis on organic communities. The quantitative work of the Danish marine zoologist Peterson on bottom fauna, carried out for twenty-five years in the first part of this century, has been very influential both in marine ecology and ecology in general. Elton (1927) in England has also contributed much to animal ecology, with emphasis on populations and numbers of animals. Up until the time certain workers became interested in biotic com¬ munities, ecology was actually a point of view, as Clements (1918) stated, or a method of approach for the study of other problems which were con¬ sidered primary, such as evolution, adaptation and variation, or the special 1953, No. 2 June Ecology and Paleontology 141 problems of fisheries, forestry and oceanography. Workers with this atti¬ tude usually worked in ecology for a while without continuity, and often after a time quitted the field entirely. On the other hand the recognition of biotic communities opened up a field of such unique character that certain workers became stimulated by studies of these phenomena for their own sake, without any necessary relation to other problems such as those just mentioned. Such workers have not had more engaging interests, have stuck to ecology, have been active in the societies and supported journals, at least in this country, and have been energetic proponents of the science. For that reason ecology in America has been strongly colored by interest in biotic communities. This aspect of the subject has doubtless been over¬ emphasized and it has been asserted that life histories and autecology (the study of one species) are of little importance. This situation and the exces¬ sive terminology invented by some workers have alienated the interest of a large number of biologists, especially the zoologists, in ecology. Ecology by right and definition includes biogeography, much of life history studies, all autecology and the study of biotic communities as well. As a matter of fact no biotic community can ever be analyzed or understood until life history and autecological studies are made of every individual species and these data are interlaced with the usual static description of a community for a full explanation of its dynamics. Full study of a biotic community would require large teams of workers and none has ever been made. It is well recognized that in the study of natural communities of or¬ ganisms botanists have progressed further and faster than zoologists. As Elton (1927) has pointed out, the reasons are two. Taxonomy is a huge problem to ecologists and since there are fewer plant than animal species, a working knowledge of plant taxonomy was attained by botanists first. The taxonomic task is still far from complete in either field, but gaps on the zoological side are much greater. Secondly, plants do not move above and their associations are much more stable and infinitely easier to study. For purposes of collection one does not have to trap a tree or shoot a little flower. Wheeler (1902) said that the attitude of botanists and zoologists towards ecology differed considerably due to the scope of their subjects; the former are concerned with organisms which are relatively simple in organization and in their responses to the environment, while animals are highly organized, with complicated nervous systems and characteristics known as instinct and intelligence. He said that the different viewpoints were exemplified by the difference of problems of '"plant societies” and social animals. In this country Clements and Shelford have actively prosecuted and promoted research in ecology since the early years of the twentieth cen¬ tury. Their central interest has been in the community aspect of life. S. A. Forbes, Birge and Juday, Pearse, Alice, Chapman, Coe, T. C. Nelson, Taylor and others have actively carried on ecological work with special relation to limnology, fisheries, parasitism, insect pests, animal sociology, oyster bi¬ ology and wildlife management. Bessey, Weaver and Cowles were active on the botanical side. The earlier work of botanists as initial builders of ecology has been briefly related by Clements (1905). The contributions of ecologi¬ cal workers from other parts of the world are discussed by Chapman (1931), Pearse (1939), Clements and Shelford (1939) and Alice, et aL (1949). Taylor (1936) has given an interesting discussion of the rela- 142 The Texas Journal of Science 1953, No. 2 June tion of ecology to the other sciences and its importance to the various phases of conservation and human welfare in general. Gislen (1930) wrote a care¬ ful summary of the development of marine "sociology.” Workers in ecology are now numbered in thousands. The ecological advance is along a broad front and the fields are many and diverse. The fields of fisheries, forestry, conservation, wildlife management, range man¬ agement, pest control and other biological subdivisions are essentially branches of applied ecology. The experimental evolutionists and geneticists have turned to ecology for answers to recently discovered problems. The relationships of oceanography to ecology are too well-known to need further comment. The growing liaison between marine ecology and paleontology {vide infra) is another example of the general spread of the ecological point of view and the recognition of its value. PALEONTOLOGY AND ECOLOGY The special task of the paleontologist is to read the history of life on the earth, not only with respect to the kinds of organisms that lived on it, but the conditions under which they lived, their associations with one an¬ other, and the geologic time during which they lived. Paleontology started as a science, hand in hand with geology, in the early eighteenth century when the chronology of geological formations first received attention. As soon as the idea of successive origin of rock layers was grasped stratigraphic geology began. It was early recognized that the same formations from different locali¬ ties could be identified by their fossils. This simple fact gave great impetus to the study of stratigraphy and it has been heavily relied upon to relate the sequence or continuity of formations in distant localities. In spite of the many puzzles and gaps in the earth’s surface record, the paramount fact certifying the credibility of the geologists’ story of the earth is the internal consistency of the vastly complex pattern of geological history, as it has been presented. Geologists are driven to filling the gaps in stratigraphic history and ironing out the inconsistencies. For instance it is well known that two formations of different lithic characters may be formed at the same time in separate localities and the fact can be proven with fossils. On the other hand, fossils may be quite dissimilar in the two localities, due to differences in the environments at the time the organisms were alive, and the subsequent existence of a difierent complex of life in the two places, or because the processes of fossilization may have been different and selec¬ tive. In either case the geologist has arrived at an impasse and, although he may feel strongly that the two layers are from the same horizon, he does not have the evidence. The status of his knowledge is too incomplete and he needs more. This is an example of why paleontologists have turned to modern ecology for information on the complex inter-relationships of or¬ ganisms to their environment. This information cannot be gotten from the past; it must be gathered from life today and utilized with care and due caution, in backward projection, so to speak, for the better interpre¬ tation of the life of organisms long since dead. In this way it is to be hoped that fuller understanding of the facts, meanings and implications of the fossil record can be deduced. The fossil record shows only a small fraction of the life that formerly existed — how small no one knows. Furthermore, it gives a biased picture of associations of organisms predominated by those containing hard parts. 1953, No. 2 June Ecology and Paleontology 143 The relative numbers or species masses of animals and plants which lived in the various past environments were doubtless quite different from what the fossils show. Most organisms lived and died without leaving a trace. Yet they had effects upon the environment, upon the sediments and upon their associates which later became fossils. The various difficulties encoun¬ tered in paleoecological studies have been outlined by Wilson (1951). A knowledge of the life processes of the organisms which left fossil remains would enable geologists to tell a great deal about the environments where they originally lived and about the effects of the organic complex upon the sediments. They tell something about depth, temperature, salinity, consistency or texture of the bottom, whether it was aerobic or anaerobic, acid or alkaline, reducing or oxidizing, or variable in all these character¬ istics, and whether deposition was slow or fast. A great deal is already known about such matters, but from marine ecology paleontologists hope to learn considerably more. In summary, a clearer picture of life groups of the past is needed to supplement the hazy and somewhat distorted view shown by fossils. There¬ fore, geologists must turn to ecological studies of living plant and animal communities for principles and rules to guide them in drawing conclusions about the organic complexes of bygone ages. Paleontologists hope to con¬ struct a reasonably correct picture of paleoecology, using both geological and biological knowledge as a guide. Certain difficulties beset application of ecological principles to paleon¬ tology. Ecologists have not studied ecology for the benefit of geologists. The ecologist tramps determinedly along a shellbank, taking data on the small mass of living material present, while practically always neglecting the vast assemblage of shells and its characteristics which the living mat¬ ter has produced throughout the years. Ecologists study how organisms live, little of how they die and nothing of what becomes of the remains. All three of these matters are of importance to the paleontologist. By the same token the geologists have not striven greatly to bridge the gap. Al¬ though there has been considerable talk and writing, geologists have scarce¬ ly deigned to study species less than 100,000 years old or, as one zoologist has put it, ''anything they so charmingly call Recent.” Nevertheless, work and thought upon the relations of ecology to paleontology is not new. Semper (1881, p. 137) called attention to the fact that the mode of life of the more recent fossils would be much easier to reconstruct than that of the more ancient forms. Forbes (1844) very early connected geology and marine ecology. Later, but still before the name ecology was adopted. White (1893), Walther (1893-94) and Grabau (1899), pointed out the relations of ecology to phases of geology. The last two writers called the subject bionomy and both emphasized the particular importance of marine bionomy. In fact, Grabau was so impressed with the relationship that he included marine bionomy in the geological sciences, saying: "Marine Bionomy is that division of thalassography or oceanography which deals with the nature and distribution of marine organisms, and their relation to the environment. It is a strictly geological study, for thalassog¬ raphy itself is a branch of physiography, which in turn is that branch of geology which deals with the present surface features of the earth, and the causes which have produced them. Marine bionomy is, in fact, the study of the paleontology of the present geologic epoch in its marine aspect, carried on under the most favorable circumstances, by contemporary ob- 144 The Texas Journal of Science 1953, No. 2 June servers.” The idea is a little extreme, but it certainly expresses the essential continuity of life phenomena and the essential relation of marine ecology and paleontology. Case (1905) considered "Oecological Features of Evolu¬ tion.” Adams (1913, p. 11) said, "The ecology of living animals is only the latest chapter in the history of this subject; the preceding chapters will contain a history of the indefinitely long series of ecological responses which have taken place in the geologic past. Here is where the ecologist and paleontologist and geologist find common ground. The ecology of liv¬ ing animals must furnish us with whatever firm basis we have for the inter¬ pretation of the conditions of life in the past, upon which the paleontolo¬ gist, stratigrapher, or paleogeographer must depend, at least in part, for his interpretations.” Starting in 1900, Dr, T. Wayland Vaughan carried on extensive studies of the geology of coral reefs of Hawaii and the Florida Keys, and studies of the living animals as well, including larval stages, associations, rate of growth, etc. He was thus one of the few workers who combined studies of living and fossil organisms. His publications in this field cover a period of over thirty years. Many of the important papers are cited in Vaughan (1940). Clements (1918) and Clements and Chaney (1923-193 5) discussed the principles and methods of paleoecology of plants and Chaney (1925) applied community studies to fossils. Case (1926) continued to publish in paleoecology. He spoke of the growing recognition of the necessity of studying the environment of fossil groups, and said (p. 190), "Nothing is better established, amidst all the confusion of the discussions as to method of evolution, than the fact that the environment changes before change ap¬ pears in the organic forms. Equally well established is the fact that the geo¬ logical cycles, large and small, have been repeated with singular persistence and identity of conditions. This recurrence of very similar inorganic envi¬ ronments has consistently resulted in very similar responses from life; . . .” "Admitting as a distinct thing the gradual but persistent advance in complexity of life form with the passage of geological time, we may say that the response of life to its environment has been a repetitive process. This is saying no more than that there has been a repetition of adaptive radiations from different stages of advancing lines.” The National Research Council of the United States had a committee on Paleoecology which published two reports under the chairmanship of Twenhofel (1936, 1937). Clements and Shelford (1939, p. 4) discussed paleoecology, saying, "Development is a continuous process, and hence its division on the basis of time past and present can be justified only on the score of convenience. . . . This fact has naturally not passed unnoticed by paleontologists, but it is the peculiar province of paleoecology to insist upon the basic essence of continuing development and to emphasize the fact that the present is but a passing stage of this.” The same writers continuing (p. 5) say "... the key to the past is fashioned by the present, to use these terms in their everyday significance. On the other hand, the present is the sole heir to the past, and no adequate understanding of it is possible without tracing the continuity of developmental processes from the one to the other.” The latter statement raises a point not often mentioned, namely, the value of paleontology to ecology. Pearse (1936) in a scholarly treatment of the old evolutionary prob¬ lem of the migration of animals from sea to land, applied ecological infor- 1953, No. 2 June Ecology and Paleontology 145 mation to the discussion and analysis of the matter. Gunter (1947a, b) dis¬ cussed the import of salinity relationships of present day marine animals to paleoecology and the paleontological significance of catastrophic mortalities in the sea. In 1940 a Sub-Committee on the Ecology of Marine Organisms was established within the Division of Geology and Geography of the National Research Council under the chairmanship of Dr. Harry S. Ladd. This com¬ mittee was founded chiefly due to the efforts of the late T. Wayland Vaughan. It has changed names several times and still functions. The chief task now is preparing a Treatise on Marine Ecology and Paleoecology, which should be published within a few years. The marine environment, especially the shallow, marginal areas of the seas, is much richer in life than the fresh water environments and marine sediments contain a richer assemblage of fossils than fresh water sediments. Furthermore, most of the permanent sediments are of marine origin, while the majority of those that were laid down in fresh water have been eroded away and redistributed. In addition marine waters formerly covered large parts of present lands. For these reasons marine ecology is of paramount im¬ portance to geologists as an interpretive tool. It must be remembered that all paleoecology is based upon the funda¬ mental assumption that any given group of organisms lived in the past in an environment essentially similar to that in which they or their counter¬ parts live today. The validity of this assumption is borne out by the fact that students of entirely different groups of organisms check each other in their paleoecological interpretations. For example, fossil pelecypods found in a clay bed may be associated with other fossil organisms whose modern relatives inhabit a muddy bottom. The field of marine ecology pays largest dividends to the student of Pleistocene marine faunas. So few organisms have become extinct since the Pleistocene that the paleontologist familiar with living marine faunas can do a rather complete job of interpreting conditions under which the Pleisto¬ cene forms lived. If he analyzes Pleistocene faunas, he can eliminate most, if not all, of the "foreign” elements (those re-worked from some other en¬ vironment) and determine which members of the "death assemblage” ac¬ tually lived together. Then, by comparing with an identical or very similar living assemblage, he can confidently postulate the conditions under which Pleistocene fossil-bearing beds were deposited. Indeed, the presence of cer¬ tain types of transported organisms may add to rather than detract from knowledge of the environment, for these "foreign” fossils may give some information about the strength of the current that brought them in, the nearness of land, or the nearness of fresh or brackish water, etc. The insight given by marine ecology to Tertiary paleontology is almost as high as in the case of the Pleistocene. However, as we go down (backward) in the Tertiary, the proportion of extinct species increases, but in almost every case there are closely related species or genera in the Recent fauna, and it is still possible to obtain a fairly complete concept of the conditions that ex¬ isted in the Tertiary. It should be pointed out that the extinct species, par¬ ticularly those with short geologic ranges, are the most valuable for age determination, whereas the species represented in living faunas are obviously the best for ecological interpretation. Though the value of a knowledge of present day ecology to the paleon¬ tologists decreases progressively in the pre-Tertiary periods of geologic time, 146 The Texas Journal of Science 1953, No. 2 June the need for ecologic interpretation remains. For the other periods, charac¬ teristics of the sediments rather than evidence from living species must be used. These criteria include lithologic characters (texture, grain size, com¬ position, etc.) and sedimentary structures (mud cracks, ripple marks, etc.) of the containing rocks. For example, relatives of organisms that today and in Tertiary time consistently lived on muddy bottoms can be reasonably presumed to have inhabited similar environments in the geologic past. When found in a different sedimentary facies, such as coarse sandstone, they may be assumed to be "foreign” or out of place. Some assemblages that lived dur¬ ing the Mesozoic periods, such as those of oyster beds, are similar to as¬ semblages on oyster beds today, but there are other assemblages made up of organisms that cannot be compared with living relatives. Some groups of organisms, such as the conodonts, have no known living close relatives. In cases of this sort paleontologists must rely upon evidence from associated organisms and on sedimentary criteria. Actually, a knowledge of ecology and a knowledge of sedimentation complement each other and are insepar¬ able. This interdependence becomes increasingly important in progressively older rocks. Many paleontologists, particularly those working in Paleozoic rocks, have ignored ecology and as a result have made erroneous and fan¬ tastic interpretations. Some Paleozoic paleontologists, particularly those of the older school, have insisted that all differences between fossils reflect differences in age, when actually the differences may be only those of facies. In pre-Mesozoic periods the task of interpreting the ecology of the past be¬ comes increasingly difficult and the paleontologist studying organisms of these periods must depend entirely upon criteria such as those mentioned above. The writer is indebted to Dr. Harry S. Ladd, of the U. S. Geological Survey, for many suggestions concerning this paper. LITERATURE CITED Adams, C. C. — 1913 — Guide to the study of Animal Ecology, xii + 183. The Macmillan Co., New York. Allee, W. C., H. E. Emerson, T. Park, and K. P. Schmidt — 1949 — Principles of Animal Ecology, xii + 837 pp. W. B. Saunders Co., Philadelphia. Brooks, W. K. — 1899 — The Foundations of Zoology, viii + 339 pp. The Macmillan Co., New York. Buffon, G. D. D. — 1749-1804 — Hisioire naturelle generale et particuliere. 44 vols. Burdon-Sanderson, J. S. — 1893 — Biology in relation to other natural sciences. Nature. 68:464-472. Case, E. C. — 1905 — Oecological features of evolution. Bull. Wisconsin Nat. Hist. Soc. 3:169-180. - 1926 — Environment of tetrapods in the late Paleozoic of regions other than North America. Carnegie Inst. Washington Pub. No. 575, pp. 211. Chaney, R. W. — ^1925 — I. A comparative study of the Bridge Creek flora and the modern redwood forest. II. The Mascall flora — its distribution and climatic relation. Studies on the fossil flora and fauna of the western United States. Carnegie Inst. W ashington Pub. No. 34P. Pp. 3-48. Chapman, R. N. — 1931 — Animal Ecology with Special Reference to Insects, x + 464. McGraw-Hill. New York. Clements, F. E. — 1905 — Research Methods in Ecology, xvii + 334. Univ. Pub. Co., Lincoln, Neb - 1918 — Scope and significance of paleoecology. Bull. Geol. Soc. Am. 29:369- 374. 1953, No. 2 June Ecology and Paleontology 147 - and R. W. CHANEY — 1923-1935 — Paleo-ecology, in Year Books Carnegie Inst. W ashington. - - - and V. E. Shelford — 1939 — Bio-ecology, vii + 425 pp. John Wiley & Sons. New York. Elton, C.- — 1927 — Animal Ecology, xx + 207 pp. Sidgwick & Jackson. London. Forbes, E. — 1844 — Report on the Moiliisca and Radiata of the Aegean Sea. Kept. Brit. Assoc. A^dv. Sci. 1843:130-193. Gislen, T. — 1930 — Epibioses of the GuUmar Fjord II. Marine Sociology, pp. 1-380. Skriftser. Ut. Av K. Svenskap. No. 4. Gosse, P. H.- — 1853 — A Naturalist’s Rambles on the Devonshire Coast. 451 pp. John van Voorst, London. Grabau, a. W. — 1899 — The relation of marine bionomy to stratigraphy. Chap. Ill, pp. 319-367, in the Paleontology ot Eighteen Mile Creek and the Lake Shore sections of Erie County, New York. Buffalo Soc. Nat. Sci. 6:99-389. Gunter, G. — 1947a — Paleoecological import of certain relationships of marine animals to salinity. Jour. Paleon^. 21:77-79 - - — 1947b — Catastrophism in the sea and its paleontological significance, with special reference to the Gulf of Mexico. Am. Jour. Sci. 245:669-676. Haeckel, E. — 1869 — Entwicklungsgang und Aufgaben der Zoologie. Genaische Zeitschr. 5:353-380. Herdman, W. a. — 1896 — Oceanography, bionomics and agriculture. Ann. Rep. Smith Inst. 1895. pp. 433-453. (Reprinted from Nature, vol 52). Lankester, E. R.— 1889 — Zoology (article) Ency. Britannica, 24:842. 9th Ed. Mobius, K.- — 1877 — Die Auster und die Austernwirthschaft, pp. 1-126. Berlin. Pearse, a. S. — 1936 — The Migration of Animals from Sea to Land, x + 175 pp- Univ. North Carolina Press. Durham. Pearse, A. S. — ^1939 — Animal Ecology, xii + 642 pp. McGraw-Hill Book Co. 2nd Ed. New York. SainT-Hilaire, I. G. — 1859 — Histoire ^enerale des regnes organiques. vol. 2, Paris. Semper, Karl — 1881 — Animal Life as Affected hy the Natural Conditions of Existence, xvi + 472 pp. Appleton and Co., New York, Shelford, V. E. — 1929 — Laboratory and Eield Ecology, xii + 608 pp. Williams & Wilkins Co. Baltimore. - — 1937- — Animal Communities in Temperate North America, xiii + 362 pp. Univ. Chicago Press. 1913. 2nd Impression, xiii + 368 pp. Taylor, W. P. — 1936 — What is ecolosy and what good is it? Ecology 17:333-346. Twenhofel, W. H. et al — 1936 — Report of the Committee on Paleoecology 1935- 1936. Division of Geology and Geography, National Research Council pp. 1-64. Mimeographed. Washington. - - - 1937- — Report of the Committee on Paleoecology 1936-1937. Division of Geology and Geography, National Research Council pp. 1-63. Mimeographed, Washington. Vaughan, T. W. — 1940 — Ecology of modem marine organisms with reference to paleogeography. Bull. GecA. Soc. Am. 51 -433-468. 8 figs. Verrill, a. E. — 1873 — Report on the invertebrates of Vineyard Sound and adjacent waters. Rept. U.S. Fish Comm., 1871-72:295-544. Walther, J. — 1893-94 — Einleitung in die Geologic als historische Wissenschaft. I. Bionomie des Meeres. II. Die Lebensweise der Meeresthiere. xxx +531 pp. G. Fischer. Jena. Warming, E. — 1909- — Oecology of PGnts. An Introduction to the Study of Plant Comanunities. xi + 422 pp. Oxford University Press. (A revision of the earlier Plantesamfund; 1895, in Danish) Wheeler, W. M. — 1902— "Natural History,” "Oecology” or "Ethologv”? Science, N.S., 15:971-976. White, C. A.— 1893 — The relation of biology to geological investigation. Ann. Rept. U.S. Nat. Mus., 1892:245-368. Wilson, J. L.— 1951^ — -Paleoecology. Texas Jour. Sci. 3(l):58-65. RADIOACTIVE ISOTOPES AS TRACERS OF ANTIBODIES LUDWIK ANIGSTEIN University of Texas, Medical Branch, Galveston The rapid developments in nuclear physics have provided us with radio¬ active isotopes, which in addition to their application in medicine have proved a most important scientific tool as tracers of basic body metabolism and of the channels through which antigens and antibodies are incorporated into our tissues. Each of the 98 known elements lying in the atomic table between the hydrogen and the uranium has at least one radioactive twin element having the same chemical property, but different atomic weight. These are radio¬ active isotopes"' which in nature occur in ores, but may be produced in the laboratory by the bombardment of atoms with particles from other atoms. The newly formed atom may be stable or may disintegrate over a period of time ranging from a minute to a billion years. These disintegrat¬ ing elements which emit nuclear energy (gamma and other rays) are radio¬ active. Due to the constant emission of energy its intensity drops steadily, and when it falls to one-half of its initial value, the "half-life” is reached. The time required for this diminution by half is characteristic for each radio¬ active isotope. For example, the half-life of Phosphorus (P^^) is 14.2 days; that of radioiodine 8 days and for Carbon (C^^) 5,000 years. The measurements of radioactivity are accomplished by the electronic device (Geiger-Miiller counter) which registers the number of nuclear explosions per second. As a source of therapeutic radiation the isotopes offer greater localization of rays in the desired tissues or organ than the irradiation by X-rays. As shall be presented later, this selectivity can be increased by bind¬ ing the radioisotopes with substances showing particular affinity to the organ chosen as a target. These substances are antibodies, essential elements of our existence, and their nature and mode of formation constitute the vast subject of immunology. ACQUIRED IMMUNITY In our struggle for existence we are unaware of the fact that from the first day we live in a world of microorganisms which are potential enemies. Some of these organisms are parasites which for the sake of their own survival are provided by nature not only with resistance, but also with offensive powers against the animal host. Usually these invasive forces are in a dormant state, but under certain circumstances, when the defenses of the susceptible host are lowered, a cold war between the micro- and the macro-organism may lead to an open conflict. Whenever our first line of defense (skin or mucous membrane) is broken and invaded by such mi¬ crobes as a malaria parasite, streptoccoccus or influenza virus, they will be * Prepared originally at the request of the Off'ce of Naval Research, Washington, D. C. **Name given by the British physicist Frederick Soddy in 1912 to these variant atoms of the same element ( ''isos”-same and "topos”-place) . 148 1953, No. 2 June Radioactive Isotopes as Tracers 149 treated by the living tissue as foreign elements which should be eliminated. This tendency of elimination of a foreign substance is an inherent prop¬ erty of a living organism. If successful, the host will overcome the mi¬ crobial invasion and survive the infection with immunity tO' a subsequent infection of the same kind. This striking phenomenon became the corner¬ stone of a new branch of biology, namely immunology, which developed into modern immunochemistry. We have reason to assume that the state of acquired immunity is associated with a profound transformation in the biochemical pattern of the surviving host, particularly in the structure and configuration of the molecules of the body proteins. SEROLOGICAL REACTIONS It was found that when the blood serum of immune animals is mixed with the disease producing bacteria, the latter are clumped together or may be dissolved. These reactions, which may be reproduced in a test-tube, are characterized by their specificity; i.e., the clumping (agglutination) will take place only with the causative agent of the particular disease or with related organisms. These strange substances which appear in the blood and tissue fluids of immune animals as a response to infection are called anti¬ bodies, since they act as bodies against the invading microbes. These as well as any other foreign substances which may induce the formation of anti¬ bodies are called antigens. NORMAL ANTIBODIES Whereas the above phenomena are active and specific responses of the host animal, the blood of animals with no direct contact with the infective agent or with other antigenic factors, also contains substances which act as antibodies. The origin and formation of these "'normal” antibodies are more puzzling than the actively produced antibodies by a known antigen. One thing is certain, namely in both instances the antibodies are chemi¬ cally serum proteins belonging to the "globulin” class. Furthermore, no essential differences will be found between antibodies and so-called "normal” globulins. ANTIBODY FORMATION The formation of antibodies is by no means limited to microbial in¬ fections, but may be induced by manifold substances injected into the ani¬ mal. When proteins are introduced into the digestive tract, the digestive juices split and decompose them into simpler products which are no' longer able to produce antibodies; in other words, they cease to be antigenic. If, however, the parenteral route (outside of the digestive tract) is chosen, then the formation of antibodies starts immediately after the injection of the antigen. Some antibodies are formed and deposited at the site of injec¬ tion, whereas others are gradually liberated from various tissues, mostly spleen, lymph nodes and bone-marrow. In most cases the rabbit is used for the production of immune sera by repeated injections of a suspension of the desired tissue from another animal species. The produced antibodies against the respective tissues can then be evaluated in the rabbit serum by adding to the serum the tissue suspension used for immunization. The resulting cloudy precipitate consists of antigen particles clumped together with the antibody particles. This 150 The Texas Journal of Science 1953, No. 2 June precipitation test represents a conventional serological tool for detection of antibodies and is based on their specificity and on their combining power with the homologous antigen used for the manufacturing of the antiserum. The mechanism of this intricate phenomenon led to various theories of which the classical lock-and-key theory of Paul Ehrlich tried to solve the mysteries of immunity and chemotherapy. According to Ehrlich, antibodies are normal constituents of our protoplasm and act as chemical groups or receptors responsible for the fixation of the antigen. In the light of the modern immunochemistry the molecules of the antibody do not necessarily fit the antigen as a single key-lock combination, but may rather be com¬ pared with a series of master keys fitting a series of locks (Hirszfeld, 1948). In this regard, the theories concerning antibody formation advanced by in¬ vestigators such as Breinl, Haurowitz, Boyd, and more recently by Linus Pauling, tend to replace the chemical concept of Ehrlich’s rigid receptors by dynamic intermolecular forces. For a better understanding, antibodies can be compared with chemical substances and serological reactions with ordinary chemical reactions. According to Pauling, each antigen molecule attracts 2 antibody molecules, this process continuing until the framework of molecules reaches macroscopic size, constituting a precipitate, which re¬ sembles an ordinary chemical precipitate. The prevailing theories of the structure of antibodies represent the surface configuration of an antibody molecule as complementary shaped to that of the antigen molecule. When antigen is injected into an animal, its molecules which are retained by certain tissues (bone-marrow, spleen, liver) modify the shape of normal protein globulins in adapting them to the shape of the antigen molecules. These modified globulin molecules are the antibodies which differ from normal serum globulins only by their property of combining specifically with the corresponding antigen. Without going into the pro and cons of the theories of antibody-antigen reactions, we have to admit that the controversy in the opinions of prominent immunochemists beginning with Ehrlich is still alive to date and that the various theories remain in a conflicting state. Pauling’s concept and his tri-dimensional presentation of the dynamic anti¬ body formation has didactic merits, and has therefore been offered here for the reader fresh to the field, although the crucial experiment is still missing. ANTI-ORGAN SERA The structural and functional complexity of our body is manifested by specialization of its tissues and organs. The framework of our tissues is composed mostly of proteins which display a diversity of biochemical patterns specific to the organ. These proteins can be differentiated serologi¬ cally just as the organs are identified by their structure and function (Landsteiner, 1945). Even within the same animal species there is a multi¬ tude of antigenically different proteins peculiar to the various organs. This organ specificity makes it possible for us to produce specific anti-organ sera from such laboratory animals as rabbits by repeated injections with tissue suspensions (see Fig. 1). The rabbit is then bled, the serum separated from blood cells is used for serological reactions. TOXIC EFFECT The concept of anti-organ sera is about half a century old and origi¬ nated with Metchnikoff who showed that guinea pigs injected with spleen tissue of rats yield a serum which if injected into normal rats has a toxic. 1953, No. 2 June Radioactive Isotopes as Tracers 151 Radioactive Anti-Organ Immune Serum detrimental effect on the rat’s lymphocytes (blood white cells and main components of the spleen) . In making history, the "Early Father” of im¬ munology was perhaps unaware of the intrinsic values of his observation and of the mechanism of the phenomenon which is now recognized as a classical experiment representing a drastic demonstration of antigen-antibody combination. Giant protein molecules were formed in the rat by inter- molecular forces which combined the organ specific antibody with the homologous antigen (spleen of the rat). In the light of our modern con¬ cept, the protein molecules of the rat spleen induced an adaptation of the guinea pig’s molecules in molding them to the shape of the antigen. Such surface adaptation made this fixation possible. Under certain conditions this irreversible process may involve the entire organ leading not only to a toxic effect, but to the abolishment of its physiological functions. In the case of the rat spleen as the main center of the defense mechanisms, the injected anti-spleen serum may cause an "immunological paralysis” of the organ. Consequently, the animal is deprived of its main weapon for combating infections. This drastic demonstration of the potentialities of anti-organ sera and their strong affinity to the homologous tissue can be compared with the selective activity of certain drugs which if applied in massive dose may be damaging to the tissues and fatal to the host. Stimulating Effect-—On the other hand, small doses of the same drug may exert a stimulating, beneficial effect. In applying this pharmacological prinicple Metchnikoff was successful in promoting resistance to infection in animals treated with small quantities of anti-organ sera. It took 2 5 years 152 The Texas Journal of Science 1953, No. 2 June to revive this problem by one of his students, Bogomolets, who was able to show that extremely small quantities of ACS (anticytotoxic serum) which contained antibodies against spleen and bone marrow stimulated the functions of the spleen, marrow and the whole physiological system of the connective tissues. Work done in this country has shown that although ACS is not a specific cure for any disease, it is nevertheless a stimulator of the body’s natural abilities for defense and repair. Minute amounts of the serum when injected into the skin protected guinea pigs against spotted fever and typhus (Anigstein et al). The potentialities of anti-organ sera, their possible clinical application and particularly their use as tools for the study of defense mechanisms became the subject of extensive investigations (see reviews by Pomerat, 1946; Leake, 1946; Gardner and Speaker, 1951), In this category the immunological approach to the mechanism of diseases like rheumatic heart or inflammatory condition of kidneys (glomeru¬ lonephritis) tends to incriminate antibodies produced by the individual against his own tissues. According to this theory recently postulated by Pressman (1951) the process of autoimmunization leading to fixation of antibodies with the tissues involved is responsible for the disease, TRACING OF ANTIBODIES BY RADIOACTIVE ISOTOPES It can be seen from the foregoing that the rapid progress of immuno- chemistry reached a phase where the classical chemical methods are inade¬ quate to answer some fundamental questions without further speculation. Whereas the demonstration of antigen-antibody compound in a test tube is a freshman’s exercise, the direct evidence of this phenomenon in living tissue was made possible by the use of radioactive isotopes as tracers coupled either with the antigen or antibody. The new methods of tracer chemistry made it possible to label antibodies by coupling them with radioactive sub¬ stances without destroying the specific activity of the antibody. Thus anti¬ sera against various rat organs were prepared in rabbits by repeated injec¬ tions of tissue suspensions from spleen, kidney, lung, liver, and pancreas (see Fig, 1). The antisera (globulins) were then tagged with radioactive iodine and injected into normal white rats. These were sacrificed at inter¬ vals of several days and their tissues tested with the Geiger-Miiller counter for radioactivity. When antikidney serum was injected, a definite accumu¬ lation of radioactivity was found in the kidney, exceeding considerably the radioactivity of other organs. Similarly, when the rat was injected with tagged antiliver serum, higher values were recorded by the Geiger-Miiller counter for liver tissues when compared with other organs. In other words, the specific rat antibody when injected into a rat will aim at the respective organ and carry the radioactive element which will be deposited there in larger amounts than in other tissues. Since it was shown that iodine at¬ tached to the globulins presents a fairly stable compound, it can be con¬ cluded that the accumulation of radioactivity in tissues is a visible evidence of the equally concentrated specific antibodies. Furthermore, the persistence of the antibodies in the blood and various organs can be estimated. Here again the measurements of radioactivity are the guiding factor in determin¬ ing the biological half-life of the antibodies, preceding their disappearance from the body. This approach may have an important practical application in evaluating the length of time over which, for example, the injected globulins against measles or poliomyelitis will persist in the circulating blood as a protection against these diseases. 1953, No. 2 June Radioactive Isotopes as Tracers 153 CONCLUSION It may be concluded that the radioactive isotopes are most important scientific tools which have uncovered to a great extent some of the mysteries surrounding the antibodies which over the past five decades were a field of wide speculation. It is reassuring that the modern findings can be integrated with the older concepts of the specificity of antibodies and their combin¬ ing power with the homologous tissues. Furthermore, new data were supplied in using the isotopes as tracers of the anatomical localization of the tissue antibody by which it evolved from mystery into a visible reality. Another aspect presents itself, namely the consideration of the antitissue antibody as an inert vehicle which will carry the radioactive element to the homolog¬ ous organ chosen as a target of ultimate destination. A concentration of radioactivity of possible therapeutic value for an organ struck by malignancy can therefore be expected. REFERENCES Anigstein, L., D. M. Whitney, and J. Beninson — 1948 — Inhibition of experi¬ mental typhus and spotted fever by intr? dermal inoculation of antiorgan sera and of certain normal sera. Tex. Rep. Biol, and Med. 6: 87-96. Bogomolets, A. A. — 1943 — Antireticuiai -cytotoxic scrum as a means of pathogenic therapy. Aw. Rev. Soviet Med. 1; 101-112. Boyd, W. C. — -1947 — Fundamentals of immunology. 503 pp. Gardner, Th. S., and D. M. Speaker — 1951— A critical evaluation of antireticular cytotoxic serum (ACS). Tex. Rep. Biel, and Med. 9:448-490. Haurowitz, F. — 1952 — The mechanism of the immunological response. Biol. Rev. 3:247-280. Hirszfeld, L. — 1948 — Immunologia ogolna. (General immunology). Stockholm. 540 pp. Landsteiner, K. — 1945 — The specificity of serological reactions. Harvard University Press. 310 pp. Leake, C. D.— 1946 — -The reticulo-endothelial system and resistance to disease. Hawaii Med. Jour. 5:251-256. Metchnikoff, E.' — 1900 — Sur les cytotoxines. Ann. Inst. Past. 14: 369-377. Pauling, L.- — 1940- — A theory of the structure and process of formation of anti¬ bodies. Jour. Am. Chem. Soc. 62:2643-2657. Pomerat, C. M. — 1946 — A review of recent developments on reticulo-endothelial immune serum (REIS). Quart. Phi Beta Pi. 42:203-208. Pressman, D. — -1951 — The 2one of localization of antitissue antibodies as determined by the use of radioactive tracers Jour. Allergy 22: 387-396. HYALITE (FLUORESCENT OPAL) FROM LLANO COUNTY, TEXAS ^ ROBERT M. HUTCHINSON Department of Geology The University of Texas Six to eight miles west and southwest of the town of Llano, Texas, granites of the Sixmile-type outcrop as low rounded knobs. The granite has intruded layers of Packsaddle schist and Valley Spring gneiss and out¬ crops in a roughly semi-circular pattern. Outcrops are crisscrossed by closely spaced joints systems along which the agents of weathering have rounded off and are also actively engaged in rounding off the granite. Many attempts have been made to quarry the local Sixmile granite, but most operations have been unsuccessful due to the poor rift, or grain, as it is called by the granite-workers. Opal (variety hyalite) was found lining the surfaces of joints in one of these abandoned quarries. Of 75 joints mapped in the granite quarry, three contained hyalite. Two of the three joints dip 7° SE and the other 7° NW (Fig. 1). The opal occurs as glassy fissue filling passing into translucent and whitish crusts with finely globular or botryoidal structure (Fig. 2). The mineral has conchoidal to subconchoidal fracture. Hardness is 6-6.5. Specific gravity is 2.12-2.18. Luster is subvitreous, sometimes inclining to resinous. The encrustations on the joint surfaces vary in thickness from ka mm. to 10 mm. Base of the encrustations, where attached to the wall of granite, fluor¬ esces brilliant yellowish green (Fig. 2). Tops of the crusts fail to fluoresce. Index of refraction of both fluorescent and non-fluorescent material is 1.45 0±.002. Table I gives the variation of refractive index vdth tenor of water (Winchell, 1951). TABLE I H^O 3.5% 6.33 8.97 28.04 ( Artificial) N 1.492 1.4531 1.4465 1.409 G. 2.16 2.096 2.036 1.731 1 M. J. Stewart of Llano, Texas, kindlv itave the author permission to enter quarries and map the geology. Prof. E. J. Weiss, Ceramic Engineering Department, University of Texas, ran X-ray diffraction patterns powdered samples. Prof. G. H. Ayres and Dr. E. W. Berg, Department of Chemistry, University of Texas, made available the spectrochemical laboratory on the Off-( ampus Research Center. Dr. Berg ran all spectrochemical determinations. Prof. S. E. Clabaugh, Department of Geology, Uni¬ versity of Texas, assisted in the laboratory procedures and criticized the manuscript. Prof. R. K. DeFord, Department of Geology. University of Texas, also helped with the manuscript. 154 156 The Texas Journal of Science 1953, No. 2 June TABLE T STRONGLY FLUORESCENT, NON “FLUORESCENT TO WEAKLY LLANO COUNTY, TEX^ FLUORESCENT, LLANO COUNTY, TEXAS SPECIMEN SPECIMEN SPECIMEN SPECIMEN SPECIMEN SPECIMEN SPECIMEN ' 2 3 4 ' 2 3 Si Si Si Si Si Si Si Fe Fe Fe Fe Fe Fe Fe Al Al Al Al Al Al Al Cq Ca Co Ca Co Cq Co Be Be Be Be — Be Be Mg Mg Mg Mg Mg Mg Mg Cu Cu Cu Cu Cu Cu Cu — Ti — Ti Ti Ti No No No B B — Pb Mn K FLUORESCENT NON- FLUORESCENT DAWSON CO, TEX. DAV\60N CQ, TEXAS SPECIMEN SPECIMEN 1 Si Fe Si Fe — Al Co Cq Mg Mg Cu Cu V B SpectroQrophic detarminations mode by Eugene W Berg, Dept, of Chemistry, University of Texas, Dec. 15, 1951. SPECTROGRAPHIC ANALYSIS OF POWDERED HYALITE SPECIMENS With an index of refraction of 1.4 50 ±.002 and a specific gravity of 2.12-2.18, the opal has a water content of approximately 5-6%. The maximum error of the specific gravity determination is 1-2%. With less than 10% H2O, opal usually contains some cristobalite or quartz (Win- 1953, No= 2 June Hyalite from Texas 157 chell, 1951). Under crossed nicols fragments of sieve-size 10 transmitted very small amounts of liglit and exhibited a slight twinkle of white. Spectrochemical analysis of four strongly fluorescent and three non- fiuorescent samples showed the presence of elements Fe, Si^ Mg^ Ca, Ah Be, Cu, B and Ti (Table II), The B and Ti were present in only some of the fluorescent and non-fluorescent material. Cu was about four times as abundant in the fluorescent material as in the non-fluorescent material. The X-ray pattern showed no sharp diffraction lines. There was a hazy line in the region of 4° which may indicate the presence of cristobalite. This is in agreement with the conclusions of Winchell that opal with less than 10% H2O usually contains some cristobalite or quartz. It is not the purpose of this paper to explain the cause of the brilliant fluorescence. However, should an attempt be made to explain this fluor¬ escence, two factors should be considered: (1) the absence of complete isotropism under crossed nicols of the petrographic microscope, and (2) the hazy x-ray diffraction line about 4°. Both of these suggest that the hyalite has tended to approach a crystalline structure during its deposition. The slight polarization of light exhibited by some of the grains might also be due to internal strain during contraction of the hyalite on solidifying, if the siliceous material was precipitated from solution as a colloidal gel. Samples of fluorescent and non-fluorescent opal (variety milk-opal) from Dawson County, Texas, donated by E. C. Shield, University of Texas geology student, were also analyzed spectrographically (Table If). Both samples analyzed showed the presence of the elements Si, Fe, Ca, Mg and Cu. Al, V and B were present in only one of either of the twO' samples. No information was obtained on the relative intensity of the Cu lines in fluorescent and non-fluorescent samples. It may be significant that the only material found in place was on the surfaces of gently dipping joints. From the small area of granite that was mapped at the quarry, it is not possible to say whether the joint systems of the quarry (Fig. 1) are genetically related to the cooling history and the shape of the Sixmile granite mass. The opal has been deposited at low temperatures from silica-bearing waters. These solutions were probably derived either ( 1 ) from the last stages of the cooling of the Sixmile granite or (2) during percolation of meteoric water through the granite, the silicates were decomposed and again deposited along the joint seams as crusts of opal. The latter method of formation seems the most probable. In view of the fact that the layer of fluorescent material occurs at the base of the crusts (Fig. 2), and that the Cu-content of this layer is about four times greater than that of the tops of the crusts, perhaps the heaviest element, copper, was influenced most by gravity during percolation and deposition of the opaline material. During the precipitation of the opaline material, gravity would have its maximum effect when the silica¬ bearing solutions were moving along the gently dipping joints. Perhaps this explains the presence of opal only on joint surfaces with low dip angles (Fig. 1). LITERATURE CITED WiNCHELL, A. 'N.— -1951— Elements of Optical Mineralogy, Part 11. Descriptions of Minerals. John Wiley & Sons, Inc. New York, 550 pp., p. 251. THE ECOLOGICAL DISTRIBUTION OF THE BIRDS OF THE BLACK GAP AREA, BREWSTER COUNTY, TEXAS WILLIAM LAY THOMPSON The University of Texas INTRODUCTION The Big Black Gap area of Brewster County, Texas, is a State game preserve, covering 46,800 acres northeast of Big Bend National Park. A former ranch, the area has a number of earthen tanks and one concrete stock tank, which are responsible for the presence of several birds and plants not characteristic of arid regions. The present work was undertaken in an attempt to record the avian species to be found on the game preserve, and particularly to study the ecological distribution of these birds, i.e., to relate the birds to their physical and biological environments. The data given below are based on three visits to the Black Gap area, I spent five weeks there from June 7 to July 12, and four days from December 2 8 to December 31, 1951. Dr. W, B. Davis and an assistant collected in the area for two days, March 23 and 24, 1951. A total of 49 man days was spent in the field. One hundred and five specimens of birds have been collected from Black Gap. Eighty-eight of them are in the Texas Natural History Col¬ lection at the University of Texas, and 17 are in the collection of Texas A. & M. College. Over 500 plant specimens were collected and have been placed in the Herbarium of the University of Texas, This Study was made in cooperation with the Texas Game and Fish Commission. To Fred Moore, manager of the Black Gap Game Preserve, I wish to express my appreciation for his courtesy and helpfulness during our visits to the area. I am greatly indebted to the other members of the summer field party, particularly W. W. Milstead, Ralph Axtell, Tom Corday, and J. R. Tamsitt, and to Thomas E. Kennerly, whose help in the December field work was invaluable. I wish also to thank Dr. J. Van Tyne, who generously identified sev¬ eral specimens, and Dr. W. B. Davis, who made available a spring collection of Black Gap birds. To Dr. B. C, Tharp I am grateful for his help in the identification of the plants and for his suggestions during the preparation of this paper. Es¬ pecially to Dr. W. Frank Blair I am deeply grateful for help and advice during the field work, and for his ready advice throughout the preparation of the manuscript. PHYSICAL FEATURES OF THE BLACK GAP AREA The topography of the Black Gap area is very uneven. Rolling hills, surfaced by limestone fragments, are interrupted by basaltic Tertiary lava. Wilson (1951) found the limestones to be of both the Comanche and Gulf series, extending from Glen Rose age in the Comanche to Bouquillas and Terlingua age in the Gulf series. 158 1953, No. 2 June Birds of Black Gap Area 159 Toward the eastern edge of the area, approaching the Rio Grande, the hills become highly dissected by deep canyons, leaving steep cliffs of resist¬ ant limestone between terraced slopes of the softer limestone formations. Several intermittent streams follow the valley floors. The largest of these is Maravillas Creek on the northeastern edge of the area. To the southeast, Stairway Mountain, approximately 5,000 feet above sea level at its highest point, provides a boundary for the area under con¬ sideration. The United States Weather Bureau station for Brewster County is at Alpine, but Alpine is approximately 2,000 feet higher than the Black Gap area, and the climatic conditions there are not strictly comparable to those at lower altitudes. Presidio, in Presidio County to the west, is 2,594 feet above sea level, almost the same as the Black Gap area (ca. 2,068). The climatic conditions of these two areas are fairly similar. Temperatures at Presidio range from a recorded maximum of 112° F. to a minimum of 11° F. In June at Black Gap the camp thermometer registered a maximum of 114° F. The average annual rainfall as measured at Presidio is 10.23 inches. The period of maximum rainfall is from May to September. The preceding statistics are taken from the Texas Almanac for 19 52-5 3. Thornthwaite (1948) includes the Texas Big Bend country in his arid zone, with a moisture deficiency of between 40 and 60 (moisture index -40 to -60). VEGETATION The vegetation of the Black Gap area is quite varied. Fifty-four families of plants are represented by a total of 169 species. Although the flora is predominantly xeric, a number of moisture-loving forms grow along streams and around stock tanks. No large trees are found, but woody vegetation reaches heights of almost fifteen feet along the larger water courses. Waterways are dry on the surface, except for short periods after rain, but sufficient moisture remains underground to sustain walnut, buck¬ eye, Mexican persimmon and mesquite growth in the relatively deep sand of the flood plains. The rocky limestone hills support a sparse xeric flora characterized by creosote bush, shrubby catclaw, lechuguilla, and sotol. Lava-capped hills produce a more abundant vegetation of yucca, sotol, forbs and grasses. Cacti of many sorts are abundant throughout the area. ECOLOGICAL CONSIDERATIONS According to the system established by Weaver and Clements (1938), the Black Gap area of the Big Bend falls into the desert grassland climax. Tharp (1938) placed the area in his Sotol-Lechuguilla and Inter-Mountain Valley divisions of the region which he calls Foothills and Mesa Region Westward from the Pecos River. Dice (1943) and Blair (1950) place it in the Chihuahuan biotic province, taking fauna as well as flora into considera¬ tion. I shall employ the term '"association” in referring to distinctly separ¬ able communities characterized by certain plants or certain topographical features. They are to be used merely for convenience in referring to the specific habitat of the various species of birds. With one exception, the associations are named according to the dominant plant species of each. In ECOLOGICAL ASSOCIATIONS 160 The Texas Journal of Science 1953, No. 2 June 133A Ni 3aniiinv FIG. 1. Hypothetical profile of the Black Gap area, Brewster County, Texas, showing the distribution of ecological associations in relation to topography. 1953, No. 2 June Birds of Black Gap Area 161 TABLE I NUMBER OF BIRDS COLLECTED, SIGHT RECORDS (x), CALL REC¬ ORDS (h), AND NEST RECORDS (n)lN 7 ECOLOGICAL ASSOCIA¬ TIONS. Ardea herodias Cygnus columbianus An.'is .'icrta Anas carolinense Aythya collaris Cathartes aura Buteo jamakensis Charadrius voci fetus x Capella delicata Lams atricilla Zenaidma macroura x Zenaiduia asiatka ' 1 Callipepla squamata x Coccyzus amerkanus 1 Geococcyx californianus x Crotophaga sulci rostris Bubo virginianus Chordedes acutipennis x Phalaenoptilus nuttullii 1 Archilochus alexandri x Selasphofus platycercus Colaptes cafer Dendrocopos scalaris x Myiarchus cinerascens x Sayornis nigricans Sayornis saya Pyrocephalus ruhinus Petrochelidon pyrrhonota x Corvus cryptoleucus Auriparus flaviceps 1 P saltriparus minimus Thryomanes hewicki x Catherpes mexkanus Campylorhynchus brunnekapillus 1 Salpinctes ohsoletus Mimus polyglottos x T oxostoma dor sale 3 T oxostoma curvirostre * Oreoscoptes montanus Sialia currucoides Polioptila melanura 1 Anthus spinoletta Lanius ludovicianus 1 Vireo belli n Passer domestkus Icterus Paris orum x Molothrus ater Pyrrhuloxia sinuata x Guiraca caemlea X 1 X X 1 1 X X X X X X X X n? 1 X X X 1 1 1 X l.n i n n X X 1 X l,n X X X X X l,n X X X X 1 h X X X 3n 1 1 2 n X X X X 2 X 2 1 X 1 X 1 X 2 1 2 X X 2,n X n n 1 X X 1 X X 2,11 n 1 n 1 2 n X X l,n X X X X X X 2 X n X 1 1 X X X X X 2 X . . . ranch headquarters - - - X X 1 1 1 1 P 1 3 X X X 1 Grama ■ Prickly Pear 162 The Texas Journal of Science 1963, No. 2 June TABLE I (continued) -e 0 d PQ «-< d -S (U u -d e o OJ 3 W C o