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RALPH ERSKINE CLELAND October 20, 1892-fune 11, 1971 BY ERICH STEINER MUCH OF THE WORK that lecI to the establishment of genetics as a distinct biological (discipline involved studies of Oenothera, the evening primrose. The concept of mutation, which remains central to the dogma of genetics, had its origin in the observations of Hugo deVries on Oenothera. deVries's mutation theory was challenged, however, when it became clear that Oenothera exhibited a breeding behavior that clid not conform to that of other or- ganisms. It took some thirty years before the genetic nature of Oenothera was fully explained. Ralph Cleland ma(le a major contribution to the solution of this long-puzzling problem through his discovery of chromosomal ring formation at meiosis and the subsequent proof that it is the physical basis of the atypical breeding behavior of Oenothera. Ralph Erskine Cleland was born in LeCIaire, Iowa on October 20, IS92, the first chilct of Charles Samuel and Edith Collins ClelancI. The family was of Scotch-Irish ancestry on both sides. Ralph's father, who spent his childhood on a farm in Minnesota, was a minister of the Uniter! Presbyterian Church; his mother came from a family of farmers in Ohio. When Ralph was one-anct-a-half years oIcT, his father ac- ceptecl a call from a church in downtown Philadelphia, the pulpit of which he was to occupy for forty-five years. Charles 121

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122 BIOGRAPHICAL MEMOIRS Clelanc! became active in denominational affairs, serving a term as moderator and spending many years as secretary of the Foreign Mission Board, an assignment that lect him to travel extensively in Africa, the MicicIle East, and Inctia. Ralph grew up in a low-income, urban neighborhood} where his playmates were largely children of factory workers. Ralph's father, however, insisted that the children spend their summers at a country cottage in Lehigh County, Penn- sylvania. It was here that Ralph cleveloped his interest in botany and natural history, spending much of his time roam- ing through the fields and wools. In Philadelphia, Ralph attencled Central High School where he was enrollecI in the "classical" course. He con- sidered his high school education unusual in that it was to some extent the equivalent of a college program. The cur- riculum was broactly liberal arts, the courses rigorous, and he was taught by men with recognizes] standing in their clisci- plines. He entered the University of Pennsylvania with a four-year scholarship, receiving acivancec! credit for some of his high school work. He selected classics as his major ant! history as a minor, but he also took several courses in botany. During his unclergraduate years Ralph engaged in a number of extra-curricular affairs, including participation in plays, debating, sports, the editorial board of the yearbook, ant! membership in the literary society. He believed that the latter activity contribute<] in particular to his social development cluring the college years. Undergraduate honors includecl prizes in Greek and botany and election to Phi Beta Kappa. In addition to his college studies and activities, he worked in the social programs of his father's church, an experience that impressed upon him the damaging social effects of alco- hol and led him to become a lifelong teetotaler. Upon graduation from the University, Cleland was of- fered an assistantship in the Department of Botany, even

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RALPH ERSKINE CLELAND 123 though his course preparation in biology was minimal. Nevertheless, by working summers, anc} with the air] of a Harrison Fellowship for two years, he was able to complete the requirements for the Ph.D. in three years. His doctoral research was carried out under the direction of Professor B. M. Davis, whose interests centered on cytological studies of the algae and the cytogenetics of Oenothera. Cleland chose to work on the cytological life history of a recT alga, Nemaition multifidum. As a result, he spent his summers at Woods Hole where he was able to extent! his acquaintance with other biologists. In July of lL91S, upon mailing his thesis to be published, he returnee] home to find an order to report for induction into the military service. After five weeks of train- ing, he was sent to France with a fielcI artillery unit. Shortly after his arrival abroad, he was hospitalized with influenza. By the time he recovered, the armistice had been signed and he returnee] to the United States to be dischargecI from the army in April 1919. Ralph Cleland's research career had its origin in a set of fortuitous circumstances. Shortly after his discharge from the army, he obtained an appointment as an instructor in biology at Coucher College, to begin in the fall of 1919. Without a commitment for several months, Clelanct offered to assist Professor B. M. Davis with his research. Dr. Davis was at the moment interested] in the cytology of the hybrid between a diploic! and tetraploicI race of Oenothera ant! turned the prob- lem over to Cleland. Cleland chose Oenothera franciscana, a strain that happened to be at hand, for determining the best methods of fixation and staining. The stucly of Oe. franciscana proved to be of greater interest than a mere test of technique, since the cytological preparations revealed that four of the fourteen chromosomes regularly formed a closet! circle at meiosis. This observation led to a series of studies by Cleland that were of major importance in elucidating the puzzling

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124 BIOGRAPHICAL MEMOIRS genetic behavior of Oenothera, a problem that had remained largely unsolved since it first came to light as a result of studies of the genus by Hugo cleVries at the turn of the century. Hugo (leVries, a Dutch plant physiologist, initiated studies of variation in Oenothera in T885, hoping to attack problems of evolution through an experimental approach. His results led to the publication in 1900 of The Mutation Theory,* in which he proposed that evolution of new species occurred through su~clen and spontaneous changes in one or more hereditary characters. Evidence for his theory came largely from observations of Oenothera; it was quickly ap- parent that the concept of mutation could only be valid if the strains alleged to be undergoing mutation were pure species. Were the strains of hybrid nature, then such variations, which cleVries called mutations, could simply be recombi- nants. The problem arose because strains of Oenothera bred true when self-pollinaterl, but behaved as hybrids when out- crossed. It was thus essential to establish the purity of the Oenothera species before the mutation concept couIcl be con- sidered valid and thus significant for evolutionary theory. The contradictory behavior of Oenothera remained! a puz- zle that attracted a great many investigators in the early 1900's, but their efforts met with little success until the me- ticulous genetic analysis of Otto Renner, published ire 1917, which clemonstrated that many of the oenotheras were per- manent heterozygotes persisting in this condition because of balanced lethal factors. Ralph ClelancI's stucly of Oenothera franc~scana appeared in 1922 ant! was the first step toward the explanation of the physical basis of the mechanism re- vealecl by Renner's brilliant analysis. The curious fact is that * H. deVries, Die Mulationstheorie (Leipzig: Von Veit; vol. I, 1901; vol. 2, 1903); The Mutation Theory (English translation, Chicago: Open Court; vol. 1, 1909; vol. 2, 1910).

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RALPH ERSKINE CLELAND 125 numerous cytological studies of Oenothera had been carried out cluring the previous two decades, yet no one had recog- nized that the formation of chromosome rings at meiosis was an unusual and constant feature of most of the Oenothera . . . . strains uncler Investigation. The paper on Oenothera franciscana floes not place em- phasis on the discovery of chromosomal ring formation; more attention is focused on the evidence for the purity of Oenothera franciscana ant! the general importance of species purity for the Oenothera problem. The next paper published by Cleland appeared! in the American Naturalist in 1923 and hac! an entirely different orientation. In the interim Cleland tract examined the meiotic clivision in several other strains of Oenothera and discovered that each had a characteristic chromosomal configuration involving circles of various sizes. He noted that the adjacent members in a circle of chromo- somes appear to go to opposite poles, an arrangement not likely to depend purely on chance. Further, if one assumes that homologous chromosomes go to opposite poles, then circle formation could explain the genetic results of Shull, who hac! concluded that all the genes in Oenothera belong to a single linkage group. Cleland's studies of the following years extencled the number of Oenothera strains examined. He establisher! that a wide range of chromosomal configurations occur and each remains constant for a particular strain. Moreover, it was recognizes! that some mechanism must exist to give the regu- lar arrangement of the chromosomes in the circle that leads to alternate segregation at the time of the division. Neverthe- less, at this time CIelanc! still believed that the chromosomes in the circle were unpaired; thus he failer! to recognize the cause of circle formation. Not until the 1926 paper on meiosis in Oenothera biennis and Oe. biennis sulfured d id Clelanc! specifically cite Renner's

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126 BIOGRAPHICAL MEMOIRS work and utilize the balanced lethal concept to explain the genetic behavior of Oe. biennia. It is clear that by this time Cleland was fully aware of the direct relationship between the unique chromosomal situation and the atypical genetic be- havior of Oenothera; a coherent hypothesis still remained to be developed, however. The award of a Guggenheim Fellowship made it possible for Cleland, accompanies! by his recent bridle, Elizabeth, to spenc! the summers of 1927 and 1928 as well as the inter- vening academic year in Germany in collaborative efforts with Friederich OehIkers, Otto Renner, and Hugo cleVries. A major study aimed at correlating the chromosome configura- tions in various races of Oenothera and their hybrids with their breeding behavior was undertaken with Dr. OehIkers. In this project Clelanct assumed responsibility for the cytological work, while OehIkers carried out the genetic studies. The 1- 1. ~ . ~ 1 . ~ . ~ ~ . preliminary results or one wore were reported in tneAmer~can Naturalist in ~ 929; this was followed by a full account in ~ 930 in the fahrbuch fur Wissenschaftliche Botanik. These articles presented convincing evidence that races of Oenothera ex- hibiting a circle of fourteen chromosomes at meiosis trans- mittecl the genes in single groups; the hybrids, on the other hancI, showed diverse configurations at meiosis, but with each hybrid constant in its configuration. Further, the number of linkage groups was shown to be precisely correlated with the number of pairs anchor circles of chromosomes at meiosis. Here was rigorous proof of the correlation between gene and chromosome behavior. While the breeding behavior of Oenothera could now be understood in terms of its unique chromosomal mechanism, questions regarding the nature anti distribution of the chromosomes still needed! to be answered. Cleland did not offer an explanation for the for- mation of the chromosomal circles. He continued to consider the chromosomes within a circle as essentially unpaired and

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RALPH ERSKINE CLELAND 127 as examples of telosynapsis (association of the ends of chro- mosomes), a concept that later proved to be incorrect. The explanation for circle formation was first suggested by John Belling in a 1927 paper dealing with various types of chromosome configurations observer! in Datura stramonium.* Among these was a circle of four chromosomes, the members of which could be identifiec! morphologically ant! thus recog- nized as nonhomologous. Belling reasoned that an exchange between two nonhomologous chromosomes hacl occurred, and that such a plant, possessing two original chromosomes and two that hac! interchanged segments, would exhibit a circle of four chromosomes as a result of their pairing re- quirements. The concept of segmental interchange! was the element needed to solve the last major question of the Oenothera behavior. Further, the concept of segmental interchange led Cle- lanc] to recognize that chromosome configuration couIct serve as an index of similarity in segmental arrangement, pairs or small circles of chromosomes indicating that two complexes are identical or similar while a circle of fourteen chromo- somes signifies the greatest clegree of dissimilarity between the two complexes. This suggested that chromosomal end arrangement might be useful as a measure of phylogenetic relationship anti thus lead to an understanding of the evolu- tionary history of the group. The genus Oenothera hac! long been a problem for taxonomists because of the large number of intergrading forms that hybridize freely. Cytogenetic analysis showed promise for identifying phylogenetic group- ings, which then might be a basis for a more satisfactory taxonomic treatment of the genus. * J. Belling, "The Attachment of Chromosomes at the Reduction Division in Flowering Plants," Journal of Genetics, 18(1927): 177-205. t More commonly called reciprocal translocation.

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128 BIOGRAPHICAL MEMOIRS A study of collections from natural populations through- out California initiates! this new direction of Cleland's work, which was to become the main thrust of his research for the remainder of his career. Following study of the California races, the work expanded into a cytogenetic analysis of large numbers of Oenothera collections from throughout North America; the objective was to understand the genetic ant! chromosomal structure of natural populations anct thereby trace their evolution. In 1938 Cleland left Coucher College to assume the chair- manship of the Department of Botany at Tncliana University. Here his research program on Oenothera population structure gained momentum with the support of the Rockefeller Foundation and with the aid of various research associates ant! graduate students. The progress of these studies was reported in a series of papers beginning in 1940 with "Analysis of Wild American Races of Oenothera (Onagra)," in which the various phylo- genetic groups were identified anc! described in a provisional way. The subsequent work by Cleland and his associates con- centrated on the cytogenetic analysis of over 300 collections and led to a more precise characterization of the different groups and their evolution. These studies, which extended over nearly thirty years, were summarizer! and reviewed in Cleland's book, Oenothera: Cytogenetics and Evolution, com- pleted shortly before his cleath. While the main thrust of Clelanct's research in the latter years took the direction of Oenothera population studies, he also published a number of papers on such more-or-less un- related genetic topics in Oenothera as chromosome structure and behavior, incompatibility factors, and the inheritance of cruciate petals. A number of these studies were carried out during his retirement years. It is noteworthy that Clelancl's scientific contributions extencled over a period of fifty years.

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RALPH ERSKINE CLELAND 129 His papers were consistently significant. As new problems arose, he attacked them with success, focusing on the signifi- cant and avoiding the trivial. Clelancl's distinction in research brought him national recognition and subsequent election to leadership positions . . . . . . . ~ . . In various processional sclentlilc societies as we . as numerous honors and awards. He served on many national committees clearing with scientific matters. In 1950 he assumer! the dean- ship of the Graduate School of Indiana University, at the same time continuing as chairman of the Department of Botany. He held both positions until his retirement from administrative duties in 1958. CIelancT was a member of the National Academy of Sciences, the American Philosophical Society, and the American Academy of Arts and Sciences. He served as president of the Genetics Society, The Botanical Society of America, the American Society of Naturalists, ant] the Indiana Academy of Science. Other honors included the first John F. Lewis Award of the American Philosophical Society and the GoIclen Jubilee Merit Citation of the Botani- cal Society. He was a corresponding member of the Deutsche Botanische Geselischaft and an honorary member of the Genetics Society of Japan and the Botanical Society of Korea. Cleland helc! honorary degrees from Hanover College, the University of Pennsylvania, and Indiana University. ClelancT possesses! an unusual combination of personal characteristics that undoubtedly played an important role in the professional achievement he attained. In some respects he seemed a shy man, yet he possessed a quiet self-assurance that enabled him to present his research conclusions effec- tively at a scientific meeting, even as a young scientist whose work was just getting under way. In the early years, when he undoubtedly carried a relatively heavy teaching loacl, he devotecl his summers to research, and to growing, gathering, and preparing material for study throughout the academic

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130 BIOGRAPHICAL MEMOIRS year. His consistently significant research output was un- cloubtecIly the result, not only of long hours, but of a per- sistence and steady application to the task at hand. Neverthe- less, he was always available to his students; he never gave evidence of resentment or impatience at being interrupted. His calm, unruffled personality enabled him to shift from one activity to another with a minimal lag effect, using his time efficiently. In later years, because of his involvement in national scientific affairs, he traveler! to Washington on a regular schedule and was often away from his laboratory as much as he was there. He arranged his teaching scheclule to adapt to these clemands, not infrequently returning to campus only moments before his lecture. Cleland had a high regard for the academic way of life, and particularly for creative scholarship. The fact that his three sons all chose academic careers was a great satisfaction to him. He was a conscientious teacher who set high stan- clarcls for his students. He willingly taught at the introductory as well as at the graduate level. Although not a charismatic speaker, he was nevertheless articulate, and his lectures were well organized, accurate, anct up-to-date. While many high achievers in science frequently have fragile egos requiring continuous nurture, Clelancl obtained his satisfactions from an inner conviction that his contribu- tions were significant and sound He was essentially a modest person, readily approachable, lacking any trace of an exag- gerated sense of self-importance. He was always willing to do a menial task when it was expedient. His concern and con- sideration for others were shown not only in his personal relationships but also in his support of programs that wouIct contribute to the welI-being of the community as a whole. He remained an active church member throughout his life. While on occasion his students may have consiclered him a bit straight-lacecl because of his opposition to smoking and alco-

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RALPH ERSKINE CLELAND 131 hoi, he nevertheless held their respect anct admiration. Ralph and Elizabeth Cleland lived without ostentation. Their home radiated a warm and comfortable atmosphere. They both hac! a positive, optimistic, and cheerful attitude toward life with an enthusiastic involvement in the affairs of the Univer- sity, the community, and the world as a whole. This persisted even after Mrs. Cleland became an invalicI. Clelancl had a creep interest in music. For many years he was a regular member of a group that assembler! in Alfred Kinsey's home to listen to music in a serious way. Whenever possible he attendee! the concerts and was prouct of the quality of the musical offerings at Indiana University. It was thus highly appropriate that the memorial service following his death took the form of a concert. After retiring from administrative posts at the age of sixty-five, Cleland returned to teaching until complete retire- ment at seventy. Subsequently he continuer! his research, pursuing various problems that earlier had lower priority in his research program. Ralph CIeland was the last survivor of the investigators who hac! played a major role in the unravel- ling of the Oenothera problem and who had had direct contact with most of the prominent workers in the field initiated by Hugo cleVries. It was thus particularly important that he write a book reviewing the massive Oenothera literature and providing an up-to-date critical summary of the Oenothera work. In typical fashion, the project mover! ahead on schedule and the manuscript was complete<] only a few (lays before he was stricken with a heart attack in his laboratory.

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132 DEGREES BIOGRAPHICAL MEMOIRS HONORS AND DISTINCTIONS A.B., University of Pennsylvania, 1915; M.S., 1916; Ph.D., 1919 Sc.D. (honorary), Indiana University, 1970 L1.D., Hanover College, 1957 ACADEMIC POSITIONS Goucher College: Instructor of Biology (1919-1920~; Assistant Pro- fessor (1920-19231; Associate Professor (1923-1930~; Professor (1930-1938~; Chairman of Department (1937-1938) Indiana University: Professor and Chairman, Botany Department (1938-19581; Dean of Graduate School (1950-1958) Instructor, University of Michigan, summer 1920 Instructor, Marine Biological Laboratory, summer 1925 EDITORIAL POSITIONS Editor, Plant Cytology, Biological Abstracts, 1925-1972 Trustee, B iologacal A bstracts, 1943- 1948 Editor-in-Chief, A merican f ournal of B otany, 1940- 1946 Editorial Board, American Journal of Botany, 194~1953 AWARDS Phi Beta Kappa Sigma Xi First John F. Lewis Award, American Philosophical Society, 1937 Golden Jubilee Merit Citation, Botanical Society of America, 1956 Guggenheim Fellowship, 1927-1928; Renewed, 1928 PROFESSIONAL AND HONORARY AFFILIATIONS Fellow, American Association for the Advancement of Science (Council at various times; Vice-President and Chairman of Sec- tion G. 1944) Fellow, Indiana Academy of Science (President, 1959) Fellow, American Academy of Arts and Sciences Member, Botanical Society of America (President, 1947) Member, Genetics Society of America (Vice-President, 1955; Presi- dent, 1956) Member, American Society of Naturalists (Secretary, 1938-1940; President, 1942)

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RALPH ERSKINE CLELAND 133 Member, Society for Study of Evolution Member, International Society for Cell Biology Member, American Philosophical Society Member, National Academy of Sciences Honorary Foreign Member, Genetics Society of Japan Honorary Life Member, Botanical Society of Korea Corresponding Member, Deutsche Botanische Gesellschaft Organizing Committee, Member of Governing Board, and first Chairman (1948-1949), American Institute of Biological fir - ~clences Chairman, Division of Biology and Agriculture, National Research Council, 1948-1951 Chairman or Member of many NRC committees, including: UNESCO Committee; Maize Committee;. Kimber Award Com- mittee; Agricultural Board; NRC, NSF, and Fulbright Fellowship panels or boards; Pacific Science Board; Advisory Committee. Office of Scientific Personnel (Chairman); Advisory Committee, International Organizations and Programs, Office of Foreign Secretary Member, Advisory Committee to Selective Service, 1951-1953 Member, U.S. National Commission for UNESCO, 1958-1960 Consultant, National Science Foundation, 1952-1959 Secretary-Treasurer, Association of Graduate Schools of the Asso- ciation of American Universities, 1955- 1958 Chairman, American Delegation to 7th International Botanical Congress, Stockholm, 1951 Member, American Delegation to 9th International Genetics Con- gress, Bellagio, 1953 Member, American Delegation to General Assembly, International Union of Biological Sciences (IUBS), Nice, 1953 Vice-President, NUBS, 1953-1959 President, Genetics Section, 8th International Botanical Congress, Paris, 1954 Sent with Farrington Daniels by the National Academy of Sciences to Southeast Asia as "Scientific Ambassador," 1960; visited thir- teen countries during three-month trip. Also served as consul- tant for the Asia Foundation

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134 BIOGRAPHICAL MEMOIRS B IBLIOGRAPHY 1917 A new Erythrotrichia from Woods Hole. Rhodora, 20: 141 ,15. 1919 The cytology and life history of Nemalion multifidum. Ann. Bot., 33:323-52. 1922 The reduction division in the pollen mother cells of Oenothera fran- ciscana. Am. I. Bot., 9: 3 9 1~ 1 3 . 1923 Chromosome arrangements during meiosis in certain oenotheras. Am. Nat., 57:562-66. 1924 Meiosis in pollen mother cells of Oenothera franciscana sulfurea. Bot. Gaz., 77:149-70. 1925 Chromosome behavior during meiosis in the pollen mother cells of certain oenotheras. Am. Nat., 59:475-79. 1926 Meiosis in the pollen mother cells of Oenothera biennis and Oenothera biennis sulfurea. Genetics, 11: 127-62. Cytological study of meiosis in anthers of Oenothera muricata. Bot. Gaz., 82: 55-70. 1928 The genetics of Oenothera in relation to chromosome behavior, with special reference to certain hybrids. Z. Induk. Abstamm. Vererbungsl., Suppl. Bd., 1: 55~67. 1929 Meiosis in the pollen mother cells of the oenotheras, and its prob- able bearing upon certain genetical problems. Proc. Int. Congr. Plant Sci., 1:317-31.

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RALPH ERSKINE CLELAND 135 Chromosome behavior in the pollen mother cells of several strains of Oenothera lamarckiana. Z. Induk. Abstamm. Vererbungsl., 51: 12~45. With F. Oehlkers. New evidence bearing upon the problem of the cytological basis for genetical peculiarities in the oenotheras. Am. Nat., 63:497-510. Die Zytologie der Oenothera-Gruppe biennis in ihrem Verhaltnis zur Vererbungslehre. Tubinger Naturwiss. Abhandlungen, 12: 50-55. 1930 With A. F. Blakeslee. Interaction between complexes as evidence for segmental interchange in Oenothera. Proc. Natl. Acad. Sci. USA, 16:183-89. With A. F. Blakeslee. Circle formation in Datura and Oenothera. Proc. Natl. Acad. Sci. USA, 16:177-83. With F. Oehlkers. Erblichkeit und Zytologie verschiedener Oeno- theren und ihrer Kreuzungen. Jahrb. Wiss. Bot., 73: 1-124. 1931 Cytological evidence of genetical relationships in Oenothera. Am. I. Bot., 18:629-40. The probable origin of Oenothera rubricalyx "Afterglow" on the basis of the segmental interchange theory. Proc. Natl. Acad. Sci. USA, 17:437-40. With A. F. Blakeslee. Segmental interchange, the basis of chromo- somal attachments in Oenothera. Cytologia, 2: 175-233. 1932 Further data bearing upon circle formation in Oenothera, its cause and genetical effect. Genetics, 17: 572-602. 1933 Predictions as to chromosome configuration, as evidence for seg- mental interchange in Oenothera. Am. Nat., 67:407-18. With O. Renner. Zur Genetik und Cytologie der Oenothera chica- ginensis und ihrer Abkommlinge. Z. Induk. Abstamm. Verer- bungsl., 66:275-318.

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136 BIOGRAPHICAL MEMOIRS 1934 With W. H. Brittingham. A contribution to an understanding of crossing over within chromosome rings in Oenothera. Genetics, 19:62-72. 1935 Chromosome configurations in Oenothera (grandif iora x lamarcki anal. Am. Nat., 69:46~68. Cytotaxonomic studies on certain oenotheras from California. Proc. Am. Philos. Soc., 75:339-429. Hugo deVries, 1848-1935. J. Hered., 26:289-97. 1936 Hugo deVries. Proc. Am. Philos. Soc., 76:240-50. Peculiarities of chromosome and breeding behavior in the evening primrose. Teach. Biol., 6:119-24. Some aspects of the cytogenetics of Oenothera. Bot. Rev., 2:316-48. 1937 Species relationships in Onagra. Proc. Am. Philos. Soc., 77:477-542. William Harding Longley. Science, 85:400-401. 1940 David M. Mottier. Science, 91:423-24. Analysis of wild American races of Oenothera (Onagra). Genetics, 25:63~44. 1942 The origin of bJecipiens from the complexes of Oenothera lamarckiana and its bearing upon the phylogenetic significance of similarities in segmental arrangements. Genetics, 27:55-83. 1943 John Muirhead Macfarlane. Yearb. Am. Philos. Soc., 1943:408-11. 1944 The problem of species in Oenothera. Am. Nat., 78:5-28.

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RALPH ERSKINE CLELAND 1946 137 With M. Newcomb. The growth of Oenothera plants from embryos cultured in vitro. Proc. Indiana Acad. Sci., 55:36. With M. Newcomb. Aseptic cultivation of excised plant embryos. Science, 104: 329-30. 1947 Possible advantages of cooperation between societies in publication. Science, 105:567-68. 1949 Phylogenetic relationships in Oenothera. Proc. Sth Int. Confer. Ge- netics. Hereditas SV:173-88. A botanical nonconformist. Sci. Mon., 68: 35-41. 1950 Studies in Oenothera cytogenetics and phylogeny. Introduction and general summary. Indiana Univ. Publ. Sci. Ser., 16:5-9. The origin of neo-acuens. Indiana Univ. Publ. Sci. Ser., 16:73-81. With B. L. Hammond. Analysis of segmental arrangements in cer- tain races of Oenothera. Indiana Univ. Publ. Sci. Ser., 16: 10-72. With L. B. Preer and L. H. Geckler. The nature and relationships of taxonomic entities in the North American euoenotheras. In- diana Univ. Publ. Sci. Ser., 16:218-54. 1951 Extra diminutive chromosomes in Oenothera. Evolution, 5: 165-76. 1952 With K. B. Raper, R. E. Buchanan, P. R. Burkholder, et al. Culture collections of microorganisms. Science 116: 179-80. 1954 Evolution of the euoenotheras: the strigosas. Proc. 9th Int. Congr. Genetics. Caryologia 6(Suppl.~: 1 139~1. Evolution of the North American euoenotheras: the strigosas. Proc. Am. Philos. Soc., 98:189-213. Charles Elmer Allen. Yearb. Am. Philos. Soc., 1954:392-93.

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138 BIOGRAPHICAL MEMOIRS 1955 In union there is strength. Hanover Forum, 1:26 47. The use of material. Science, 121:519-23. 1956 Cytology: the study of the cell. Am. J. Bot., 43:870-81. The International Union of Biological Sciences. Am. Inst. Biol. Sci. Bull., 6: 10-11. Analysis of trends in biological literature plant sciences (Address at 30th anniversary celebration of Biological Abstracts). Bio. Abstr., 30:2459-62. 1957 Chromosome structure in Oenothera and its effect on the evolution of the genus. Cytologia, 22(Suppl.~:5-19. The International Genetics Symposia in Japan. Am. Inst. Biol. Sci. Bull., 7:23-24. Biological sciences. Science, 125:943. Bradley Moore Davis (1871-1957~. Yearb. Am. Philos. Soc., 1957: 113-17. The distinctive characteristics of American higher education. fin: Conference on Education and Student Life in the U.S., pp. l-10. Ann Arbor, Mich.: Conference Board of Associated Research Coun- cils. 1958 Bradley Moore Davis. Genetics, 43:1-2. The evolution of the North American oenotheras of the biennis group. Planta, 51: 378-98. 1959 Protessional and educational problems of concern to biology and medicine. Q. Bull. Indiana Univ. Med. Cent., 21:50-56. 1960 A case history of evolution. Proc. Indiana Acad. Sci., 69:51-64. The S-factor situation in a small sample of an Oenothera (Raimannia heterophylla population. Z. Vererbungsl., 91:303-11.

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RALPH ERSKINE CLELAND 1961 139 Otto Renner ~ 1 883- 1 96 1 ). Yearb. Am. Philos. Soc., 1 96 1: 1 66-7 1. Supply and demand in relation to the Ph.D. Plant. Sci. Bull., 7: 1-3. 1962 Plastid behavior in North American euoenotheras. Planta, 57:699- 712. 1963 With B. B. Hyde. Evidence of relationship between extra diminu- tive chromosomes in geographically remote races of Oenothera. Am. I. Bot., 50:179-85. 1964 The AlBS in retrospect. Bioscience, 14~3) :6. The evolutionary history of the North American evening primroses of the biennis group. Proc. Am. Philos. Soc., 108:88-98. 1966 Otto Renner 1883-1961. Genetics, 53: 1~. Review, Natural Features of Indiana. Indiana Mag. Hist., 62:345~6. 1967 Further evidence bearing upon the origin of extra diminutive chro- mosomes in Oenothera hooker). Evolution, 21:341~3. The origin of closed circles of five chromosomes in Oenothera. Am. i. Bot., 54:993-97. 1968 Science: boon or bane? Proc. Indiana Acad. Sci., 77:8~93. Cytogenetic studies on Oenothera, subgenus Raimannia. spa. I. Genet., 43:329-34. 1970 The missing petal character in Oenothera and its relation to the cruciate character. Am. I. Bot., 57:850-55. 1972 Oenothera: Cytogenetics and Evolution. New York: Academic Press.