Lillie, Frank Rattray
Lillie, Frank Rattray
(b. Toronto, Canada, 27 June 1870; d. Chicago, Illinois, 5 November 1947)
Lillie’s father, George Waddell Lillie, accountant and partner in a wholesale drug company, was a man of exceedingly upright character, but without special intellectual interests. His mother, the former Emily Ann Rattray, was the daughter of a Scottish tobacco merchant who later became a Congregational minister and amateur astronomer.
An indifferent student at a boys’ grammar school, in high school Lillie was most interested in extracurricular scientific activities. High school was a time of emotional stress and religious doubts, but he was converted to the Church of England and decided to make religion his lifework. During his last year in high school he met Alexander J. Hunter, who taught him to collect, identify, and arrange insects and fossils. Both entered the University of Toronto expecting to study for the ministry. They majored in natural sciences, believing that science posed a threat to religion. During their last two years they worked with minimum guidance and literally lived in the laboratory except when discussing science and evolutionary theory, or conducting their collecting expeditions. Lillie was increasingly disillusioned by many churchmen. A. B. Macallum showed him how he could devote his life to science, a choice Lillie made during his senior year, and also transmitted to him his physiological point of view. R. Ramsey Wright imbued Lillie with his lifelong interest in embryology and recommended him, upon his graduation with honors, to work as a fellow with C O. Whitman at the Marine Biological Laboratory at Woods Hole, Massachusetts, and afterward (1891–1892) at Clark University.
In 1891, when Lillie arrived at Woods Hole, E. B. Wilson, E. G. Conklin, A. B. Mead, and L. Tread Well were conducting cell-lineage studies in an attempt to determine the exact contribution of each blastomere to the formation of larval organs. Local ponds contained abundant supplies of freshwater clams bearing eggs and embryos in their gills; Whitman suggested that Lillie study the cell lineage of these lamellibranchs for his doctoral dissertation. In 1892 Whitman, accompanied by Lillie and his other students, moved to the newly established University of Chicago as chairman of the zoology department.
During 1892–1893 Lillie was a fellow in morphology at Chicago and the following year a reader in embryology. He received his doctorate in zoology summa cum laude in 1894 with an outstanding thesis which received wide praise and established him as a young investigator of great promise. From 1894 to 1899 he was instructor in zoology at the University of Michigan and from 1899 to 1900 professor of biology at Vassar College; he then returned to the University of Chicago as assistant professor of embryology. He became associate professor in 1902, professor in 1906, chairman of the department of zoology in 1910, Andrew MacLeish distinguished service professor of embryology and dean of the newly established division of biological sciences in 1931, and emeritus professor in 1935.
In 1895 Lillie married Frances Crane, who in the summer of 1894 had been a student in his embryology course at Woods Hole. They had five daughters and one son and adopted three sons. Their Chicago and Woods Hole homes offered warmth and hospitality to a wide circle of friends, although life with Mrs. Lillie was anything but peaceful because of her extensive social work and marked changes in religious preference. The Lilies gave the Whitman Laboratory of Experimental Zoology to the University of Chicago at a time when that institution would permit solicitation of funds only for its new medical school.
Until 1916 Lillie taught an embryology course for medical students and until 1924 another for advanced undergraduate and beginning graduate students. His undergraduate teaching resulted in publication of a useful laboratory manual (1906), twice revised under slightly different titles (1919, 1923). More important, it resulted in publication of his classic book on chick embryology (1908), revised by Lillie (1919) and later by H. L. Hamilton (1952), one of Lillie’s “scientific grandchildren.” This textbook has been used by students throughout the world and remains one of the best accounts of bird development.
Lillie offered graduate seminars on the physiology of development, problems of fertilization, and the biology of sex. His approach to research training was rigorous. He suggested a problem, usually related to his own current investigations, briefly discussed possible approaches, let the student know that conscientious application and results were expected, then left him largely to his own resources until he was prepared to discuss his results and present a preliminary interpretation of their meaning.
Upon Lillie’s return to Chicago (1900) the operation of the department of zoology devolved increasingly on him as Whitman became progressively more engrossed in his own research. In 1910 Lillie was named second chairman of the department. Although adhering to Whitman’s emphasis upon original research and graduate student training as the primary mission of the department, Lillie’s administration differed from Whitman’s in two ways: the department functioned more democratically, and the scope and importance of the undergraduate program in zoology were greatly strengthened, with all members of the department teaching courses specifically for undergraduates.
Lillie resigned his chairmanship in 1931 to become dean of the newly established division of biological sciences, which included not only the usual biological science departments but also the departments of psychology, home economics, physical culture, and preclinical and clinical medicine. He was faced with amalgamating established preclinical departments with newly established clinical ones at a time when there was much disagreement about the advisability of attempting to operate both Rush Medical College and the university’s new medical school and about the basic organization and management of the latter. By the time of his retirement four years later he had succeeded.
Lillie is most widely known for his vital roles in development of the Marine Biological Laboratory, one of the strongest influences on the rapid development of the broad field of biology in America. He first arrived at the laboratory at the beginning of its fourth summer session. There was only one small building and no equipment besides a steam launch and a few skiffs. Accommodations existed for only a few investigators. There was no endowment; each summer ended with a deficit, covered initially by members of the board of trustees. Lilies returned to Woods Hole every summer thereafter for fifty-five years and during his lifetime became the leader in every aspect of the growth and development of the laboratory.
Lillie was assistant in the embryology course at Woods Hole when Whitman started it in 1893; he became course director the following year. At the same time operation of the entire laboratory began to devolve increasingly on Lillie, while the board of trustees resisted expansion and became increasingly reluctant to meet annual deficits. In 1900 Lillie was named assistant director. He immediately interested Charles R. Crane, his wife’s favorite brother, in the operation and support of the laboratory and firmly backed Whitman in convincing the corporation and board of trustees to reverse their decision to transfer the laboratory to the Carnegie Institution of Washington as its permanent marine laboratory. Lillie was named director of the laboratory in 1910, and held that position until 1926. During this period, coinciding closely with the period in which Crane served as president of the board of trustees (1904–1924) and contributed much to the support of the laboratory, Lillie and Crane convinced financiers and foundations that the laboratory deserved their strong support. Consequently, Woods Hole became a great institution for marine biology. Lillie served as president of the corporation and board of trustees from 1925 to 1942 and then as president emeritus.
In 1915, a year before the National Research Council was established, Lillie was elected to the National Academy of Sciences. In 1919, as representative of the American Society of Zoologists to the Division of Biology and Agriculture of the National Research Council, he was made a member of the executive committee and immediately received their unqualified support in his efforts to obtain increased financial support for the marine biological laboratory. He was vice-chairman and chairman of the division in 1921 and 1922, respectively. He was further active in the establishment, in 1922, of the Union of Biological Sciences, which assumed full responsibility for publication of Biological Abstracts and became Chairman of the board administering the newly established National Research Council fellowships in the biological sciences (1923), later serving on the natural sciences fellowship board when the separate programs in physical and biological sciences were combined. He served effectively on the Division of Medical Sciences of the National Research Council Committee for Research in Problems of Sex, established in 1921 to administer grants and offer advice to investigators in this area, and wrote the first chapter of the 1932 and 1939 editions of Sex and Internal Secretions.
The year he became emeritus professor, Lillie was unanimously elected president of the National Academy of Sciences (1935–1939) and chairman of the National Research Council (1935–1936), the first man hold these two key positions simultaneously. He was given this extraordinary joint responsibility in an attempt to eliminate serious controversies concerning the activities rightfully belonging to each of these two organizations. He did so with such dispatch that the task was accomplished in one year. He simultaneously strengthened relations of the Academy and Council with agencies of the federal government.
For some years Lillie had discussed with Wickliffe Rose, president of the General Education Board—and the latter with John C. Merriam, president of the Carnegie Institution of Washington, and Vernon Kellogg, chairman of the National Research Council— the need for an oceanographic institution on the East Coast. In large part the result of his labors, the Woods Hole Oceanographic Institution was formally incorporated on 6 January 1930. Financing was so well organized in advance that the building was occupied 15 June 1931 and its research ship, Atlantis, was available 31 August 1931. Lillie was president of the Oceanographic Institution from 1930 to 1939 and in 1940 received the Agassiz Medal of the National Academy in recognition of his efforts.
Lillie’s research contributions were as remarkable as his administrative accomplishments. His chronological bibliography (Willier, 1957) contains 109 titles, sixty-six of which are original works dealing with varied but always fundamental problems of development; some were published ten years after his retirement. He only rarely published research papers with his students, although after his retirement he did publish jointly with his research associates, Mary John and His Wang.
Lillie’s research was masterfully planned and executed. His work invariably opened up new areas of research. He was adept at creative interpretation and constantly strove to tie details together by broad interpretive concepts because he firmly believed that sound speculation was the only true stimulus for future research, whether or not it survived additional probing. That he never gave up active participation in research is exemplified by his service as managing editor or member of the editorial boards of several journals in biology and experimental zoology.
Beginning with his doctoral dissertation (1895), a superb descriptive study on cell lineage of the freshwater mussel Unio, Lillie’s early work (1892–1909) dealt primarily with problems of mechanisms of cleavage and of early development of eggs of invertebrates, notably those of Unio and of the marine annelid Chaetopterus. His emphasis was on how the special features of cleavage in each species were adapted to the needs of the future larva, rather than on the common features of cleavage even in different phyla, which were emphasized by many others. His studies on eggs with rigid mosaic cleavage (with developmental fates of cleavage cells already determined in early cleavage stages) led him to explore in detail the cytology of such eggs in an attempt to find some material basis for cleavage patterns, polarity, bilateral symmetry, and so on. His light microscope studies on the organization of egg protoplasm in normal and centrifuged eggs and on the extent to which differentiation without cleavage is possible in activated Chaetopterus eggs led to the conclusion that the control of early development must reside in the architecture of the ground substance of the egg, that is, on its physical and chemical properties. Thus, along with E. B, Wilson, he focused attention on the necessity for studying the ultramicroscopic organization of the egg; but even with modern ultra structural techniques there is still a long way to go in understanding the basic nature of egg organization, established in the mother’s ovary and important in control of early development.
During this period Lillie deviated briefly from his major line of investigation. One paper concerned regeneration in the protozoan Stentor; two others, regeneration and regulation in planarians; one, the effect of temperature on animal development. Of greater import was the appearance of two papers in 1903 and two in 1904 involving operations on living chick embryos in ovo. The first two described and analyzed experimentally the formation of the amnion (which fills with amniotic fluid, thus enclosing the embryo in its own miniature aquarium). By the use of heated needles or electrocautery he produced anamniote embryos which could develop normally for five to six days, and by localized destruction of specific sectors of the amniotic folds he could demonstrate convincingly certain causal relationships between them and the role of their progressive fusion in elevating amniotic folds at adjacent levels.
The second two papers primarily demonstrated the inability of parts of the embryo posterior to the vitelline arteries to regenerate following cauterization of the areas or rudiments that should have formed them; they further showed the inability of the right wing bud to regenerate following its extirpation. Although his own experimental analysis of chick embryo development was limited to these four publications, Lillie was convinced that chick embryos were suitable material for almost any type of experimental analysis of embryological problems.
From 1910 to 1921 Lillie’s research centered primarily on the morphology and physiology of fertilization in the annelid Nereis and the sea urchins Arbacia and Strongylocentrotus, resulting in the publication of eighteen papers, one book (1919), and a chapter in a book (1924). Lillie hypothesized the existence of specific combining groups in sperm and in eggs and developed a far-reaching, comprehensive “fertilizing theory” of the role of union (linkage) of such combining groups in fertilization phenomena, including activation of the egg by sperm or parthenogenetic agents, species-specificity of fertilization, prevention of polyspermy, inhibition of fertilization by what he believed to be a blood inhibitor from adult sea urchins, and so on; these results are summarized schematically in “... The Mechanism of Fertilization in Arbacia” (1914, fig. 1, p. 579). Lillie was the first to visualize the linkage of his hypothetical specific combining groups in lock-and-key fashion, analogous with hypothetical antigen-antibody or immunological reactions. He thus applied entirely new ideas to the physiology of fertilization. Although many aspects of his basic theory have had to be modified in the light of increased knowledge and understanding of the molecules and combining groups involved, many investigators still believe that interactions between specific combining groups in antifertilizin molecules on the sperm surface and specific combining groups in the fertilizing molecules of the egg cortex play essential roles in the fertilization process (see Metz, 1957, 1967, for the continuing impact of Lillie’s ideas in this research area).
Lillie’s first publication concerning sexual differentiation appeared in 1907. His interest in this research area soared in 1914, when the manager of his large Buffalo Creek farm, where he kept a herd of purebred cattle in which the birth of freemartins occurred, sent him a pair of calf fetuses still within their fetal membranes, H. H. Newman, because of his interest in twins, was first offered this material for study but he was too heavily committed to other tasks to examine it. Therefore Lillie tackled it and immediately became intensely interested in analyzing the factors responsible for development of the freemartin, which, largely on the basis of his work, was subsequently defined as a sterile genetic female born twin to a normal genetic male. The cooperative foreman of the Swift and any abattoir at the nearby Union Stockyards agreed to notify Lillie whenever he found a pregnant uterus (preferably with both ovaries attached) containing twins as young as possible.
By 24 February 1916 Lillie had carefully analyzed forty-one cases of bovine twins and announced his theory of the freemartin. His full analysis, based on fifty-five pairs of fetal twins, was published the following year (1917). This work is usually considered his most significant and enduring contribution to research (see Burns, 1961, for an authoritative review and impact of this theory), although Lillie’s explanation of causal relationships in freemartin development has been criticized by Short (1970).
Briefly, Lillie’s findings were as follows:
1. Cattle twins are two-egg or nonidentical twins (each ovary contains an ovulation site or corpus luteum).
2. The outermost extraembryonic membrane of bovine fetuses, the chorion, is greatly elongated and,in the case of twin fetuses, the two chorions (and their contained allantoic or umbilical blood vessels, especially the arteries) usually fuse at an early stage, so that blood is freely exchanged between the twin fetuses.
3. Differentiation of the gonads of genetic males into testes occurs early in fetal life, as does the differentiation of the interstitial cells of the testes, known to secrete male hormone in adult males.
4. Under such circumstances the gonads of the genetic female twin differentiate as ovotestes or as rudimentary testes, which are usually sterile.
5. The mesonephric or Wolffian ducts, and some of the mesonephric tubules, of the genetic female twin persist and develop into typical male vasa deferentia and vasa eflerentia (instead of degenerating, as they would in genetic females).
6. The Müllerian ducts of the genetic female twin usually degenerate (as they normally do in genetic males) instead of forming oviducts, uterus, and possibly the vagina (as they normally do in genetic females).
7. The degree of masculinization of the gonads and reproductive ducts in the genetic female twin is greater the earlier and the more complete the fusion of the extraembryonic blood vessels of the twin fetuses.
8. The development of the genetic male reproductive system is always normal under such circumstances.
9. In those rare instances when the extraembryonic blood vessels of the heterosexual twins fail to fuse during fetal life, the reproductive systems of both members of the heterosexual twin pair develop normally.
Lillie concluded that male hormone produced by the fetal testes of the genetic male twin enters the genetic female twin via the fused extraembryonic circulations and in the genetic female inhibits development of gonads into ovaries, stimulates development of mesonephric ducts and tubules into male-type sperm passageways, and inhibits development of Müllerian ducts into components of the female reproductive system. An almost identical theory was proposed independently by two Austrian investigators in an obscure publication (see in Science, 1919).
This theory to account for development of the freemartin condition led directly to the concept that fetal sex hormones play a comparable role in normal sex differentiation in mammals and other vertebrates, once gene control of sex differentiation causes the gonads to develop into testes or ovaries. Thus in the normal sex differentiation of mammals the duct system develops in the male direction in genetic females because of the absence of fetal testes producing male hormone during fetal life. Thus fetal castration of genetic male and genetic female mammals, such as rabbits, should result in development of typical female-type reproductive systems regardless of genetic sex. This result has been amply demonstrated (see Jost, 1954, 1961, 1971).
Lillie’s freemartin research introduced biologists to the problem of the nature, origin, and action of sex hormones at a time when almost nothing was known about them. It stimulated attempts to duplicate the circumstances producing freemartins in cattle by parabiosis of amphibian larvae of opposite genetic sex, or by grafting gonads of donor chick embryos of one genetic sex onto the choriallantoic membrane or into the coelom of host chick embryos of the opposite sex. The freemartin research led Lillie directly into collaborative work with members of the department of biochemistry that resulted in the isolation, chemical analysis, and synthesis of sex hormones.
The first known androgens were isolated in the laboratory of F.C. Koch at the University of Chicago with Lillie as colleague. These pure chemical substances were then available for injection into experimental animals to determine to what extent development of the reproductive systems of the injected animals could be modified. This work opened up for investigation the field of the biology of sex, the physiology of sex hormones and, more recently, the role of sex hormones in animal behavior-It also opened up for investigation the role in sex hormone production of gonadotropic hormones from the anterior pituitary gland and, later, of specific gonadotrophin-releasing factors from special neurosecretory cells of the hypothalamus, the nature of feedback mechanisms, and so on.
After his retirement Lillie turned to a series of investigations on the physiology of development of regenerating feathers, which, in certain breeds of fowl, such as the Brown Leghorn, are especially sensitive to estrogen, thyroxin, and similar hormones. In a series of papers published between 1932 and 1947, mostly in collaboration with Mary Juhn and Hsi Wang, Lillie added much to our understanding of the highly complex development of a regenerating feather, whose definitive structure, according to Cohen, is “...the sum of the debris of some 1.5 x 107 to 5 x 109 cells, exactly organized and engineered to the utmost precision” (1965, p. 9). The regenerating feather forms from the feather papilla or feather germ, a morphogcnetic system in miniature.
Lillie and his co-workers studied the role of induction and of the processes of twinning in feather development, attempting especially to reveal some of the factors responsible for the consistent morphogenetic and color reactions of parts of the individual feather papilla, and of feather papillae in different feather tracts, to different concentrations of hormones. Although Cohen is sharply critical of some of Lillie’s general interpretations about mechanisms of feather development and reaction to hormones, his criticisms are relatively minor when viewed against Lillie’s overall contributions to our understanding of development of the regenerating feather, examination of whose definitive structure is, according to Cohen, “a humbling process.”
Lillie received the Sc.D. from the University of Toronto (1920), Yale University (1932), and Harvard University (1938), and the LL.D. from Johns Hopkins University (1942). He was a member of several learned societies, both American and foreign.
1. Original Works. Lillie’s writings include “The Embryology of the Unionidae. A Study in Cell-Lineage,” in Journal of Morphology,10 (1895), 1–100; “Experimental Studies on the Development of the Organs in the Embryo of the Fowl (Gallus domesticus),” in Biological Bulletin, Marine Biological Laboratory, Woods Hole, Mass.,5 (1903), 92–124; “Experimental Studies on the Development of Organs in the Embryo of the Fowl (Gallus domesticus). II. The Development of Defective Embryos, and the Power of Regeneration,” ibid.,7 (1904), 33-54; Laboratory Outlines for the Study of the Embryology of the Chick and the Pig (Chicago, 1906), 2nd ed., rev., A Laboratory Outline and Manual for the Study of Embryology (Chicago, 1919), written with C. R. Moore, 3rd ed., rev., A Laboratory Outlim of Embryology With Special Refer ence to the Chick and the Pig (Chicago, 1923), written with C. R. Moore; “The Biological Significance of Sexual Differentiation—A Zoological Point of View,” in Science,25 (1907), 372–376; Development of the Chick. An Introduction to Embryology (New York, 190S, 2nd ed., New York, 1919); 3rd ed., rev., Lillie’s Development of the Chick (New York, 1952), by H. L. Hamilton; “Studies of Fertilization. VI. The Mechanism of Fertilization in Arbacia,” in Journal of Experimental Zoology,16 (1914), 523–590; “The Theory of the Freemartin,” in Science,43 (1916), 611–613; “The Free-Martin; a Study of the Action of Sex Hormones in the Foetal Life of Cattle,” in Journal of Experimental Zoology,23 (1917), 371–452; Problems of Fertilization (Chicago, 1919); “Tandler and Keller on the Freemartin,” in Science,50 (1919), 183–184; “Fertilization,” in E. V. Cowdry, ed., General Cytology (Chicago, 1924), pp. 449–536, written with E. E. Just; “General Biological Introduction,” in E. Allen, ed., Sex and Internal Secretions (Baltimore, 1932), pp. 1–11, also In E. Allen, C. H. Danforth. and E. A. Doisy. eds.. Sex and Internal Secretions, 2nd ed. (Baltimore, 1939), pp. 3–14; “The Builders of the Marine Biological Laboratory,” in Collecting Net,13 (1938), 107–108; and The Woods Hole Marine Biological Laboratory (Chicago, 1944).
An undated 33-p. MS entitled “My Early Life” provides much information on his ancestry, youth, and early education. It is filed with the F. R, Lillie reprint collection at the Marine Biological Laboratory.
II. Secondary Literature. See “Appreciations of Professor Frank R. Lillie on the Occasion of his Sixtieth Birthday,” in Collecting Net,5 (anniversary supp., 28 June 1930), 1–42; Mary Prentice Lillie Barrows, Moon out of the Well. Reminiscences (1970), copy filed with F. R. Lillie reprints at the Marine Biological Laboratory; and Frances Crane Lillie (1869–1958). A Memoir (1970), copy provided through the courtesy of B. H. Willier; R. K. Burns, “Role of Hormones in the Differentiation of Sex,” in W. C. Young, ed., Sex and Internal Secretions, 3rd ed. (Baltimore, 1961), pp. 76-158; J. Cohen, “Feathers and Patterns,” in M. Abercrombie and J. Brachet, eds., Advances in Morphogenesis (New York, 1966), V, 1–38; E. G. Conklin, “Science and Scientists at the M. B. L. Fifty Years Ago,” in Collecting Net,13 (1938), 101–106; and “The Contributions of Dr. Frank R. Lillie to Oceanography,” in Collecting Net,15 (1940), 30–31 (on the occasion of the presentation of the Agassiz Medal for Oceanography by the National Academy of Sciences); G. Fankhauser, “Memories of Great Embryologists,” in American Scientist,60 (1972), 46–55; and R. J. Harrison, “Frank Rattray Lillie (1870–1947),” in Yearbook. American Philosophical Society (1947), pp. 264–270.
See also A. Jost, “Hormonal Factors in the Development of the Fetus,” in Cold Spring Harbor Symposia on Quantitative Biology, XIX, The Mammalian Fetus: Physiologkal Aspects of Development (Cold Spring Harbor, N.Y., 1954), 167–181; “The Role of Fetal Hormones in Prenatal Development,” in Harvey Lectures, 55 (1961), 201–226; and “Hormones in Development: Past and Prospects,” in M. Hamburgh and E, J. W. Barring ton, eds., Hormones in Development (New York, 1971), pp. 1–18; C. B. Metz, “Specific Egg and Sperm Substances and Activation of the Egg,” in A. Tyler, R. C. von Borstel, and C B. Metz, eds., The Beginnings of Embryonic Development (Washington, D.C., 1957), pp. 22–69; and “Gamete Surface Components and Their Role in Fertilization,” in C. B. Metz and A. Monroy, eds., Fertilization: Comparative Morphology, Biochemistry and Immunology, I (New York, 1967), 163–236; C. R. Moore, “Frank Rattray Lillie 1870–1947,” in Science,107 (1948), 33–35; and “Frank Rattray Lillie. 1870–1947,” in Anatomical Record,101 (1948), 1–4; H. H. Newman, “History of the Department of Zoology in the University of Chicago,” in Bios,19 (1948), 215–239; A. N. Richards, “Dr. Frank R. Lillie,” a typewritten memorial read at a dinner of the National Academy of Sciences, November, 1947, two weeks after Lillie’s death (filed with the F. R. Lillie reprint collection at the Marine Biological Laboratory); R. V. Short, “The Bovine Freemartin: A New Look at an Old Problem,” in Philosophical Transactions of the Royal Society,B259 (1970), 141–147; B. H, Willier, “Frank Rattray Lillie,” in Anatomical Record,100 (1948), 407–410; and “Frank Rattray Lillie 1870–1947,” in Biographical Memoirs. National Academy of Sciences,30 (1957), 179–236; B. H. Willier, R. J. Harrison, H. B. Bigelow, and E. G. Conklin, “Addresses at the Lillie Memorial Meeting Woods Hole, August 11, 1948,” in Biological Bulletin. Marine Biological Laboratory, Woods Hole, Mass.,95 (1948), 151–162: B. H. Willier, “The Work and Accomplishments of Frank R. Lillie at Chicago,” pp. 151–153; R. G. Harrison, “Dr. Lillie’s Relations With the National Academy of Sciences and the National Research Council,” pp. 154–157; H. B. Bigelow, “Dr. Lillie and the Founding of the Woods Hole Oceanographic Institution,” pp. 157–158; and E. G. Conklin, “Frank R. Lillie and the Marine Biological Laboratory,” pp. 158–162; and W. C. Young, ed., Sex and Internal Secretions, 3rd ed., 2 vols. (Baltimore, 1961).
Ray L. Watterson