Ernest Everett Just was an early twentieth century American experimental embryologist involved in research at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, and the Stazione Zoologica in Naples, Italy. Just was known for simple but elegant experiments that supported the “fertilizing” theory of Frank R. Lillie and served as an antagonist to Jacques Loeb’s work with artificial parthenogenesis. Just’s many experiments with marine invertebrates showed that the egg surface, or ectoplasm, plays an important role in the fertilization and development of eggs.
Just was born in Charleston, South Carolina, on 14 August 1883 to Charles Frazier Just Jr. and Mary Matthew Just. His father died in 1887 and soon after the Just family moved to James Island, off the coast of South Carolina. His early education consisted of attending the small school that his mother founded and directed. Just left James Island at the age of twelve to attend the Colored Normal Industrial Agricultural and Mechanics College at Orangeburg (now South Carolina State College). In 1899 Just graduated with a Licentiate of Instruction, meaning that he was certified to teach in any black school in South Carolina. He was only fifteen years old.
Teaching did not appeal to the teenager so he traveled north, picking up odd jobs along the way until he reached Kimball Union Academy in Meriden, New Hampshire. Just finished a classical course of study in three years, during which time his mother died. The young college graduate was advised by friends and teachers to attend Dartmouth College which he decided to do. At Dartmouth, Just studied biology, history, literature, and the classics. He graduated from Dartmouth in 1907, the only “magna cum laude” in his class, with an AB degree and joined the English faculty at Howard University, Washington, DC in the fall of that same year. He was asked to take over the biology department and teach physiology in 1910, in addition to his English teaching duties. Soon after, Just became the first head of the new Department of Zoology and gave up teaching English courses.
Through a Dartmouth contact, Just communicated with Lillie at the University of Chicago about a post-graduate degree in biology. Lillie directed Just to begin research in 1909 at Woods Hole and to take courses at the University of Chicago. Work at the marine station quickly turned into a research assistantship, working side-by-side with Lillie. All of this was done in addition to maintaining a full-time teaching position at Howard. After obtaining his PhD, Just returned annually to Woods Hole as an independent researcher.
Just focused his interests on marine invertebrate eggs, both in the laboratory and in their natural setting. Because of his tacit knowledge of how marine invertebrates reproduced in oceans and estuaries, Just was able to closely match his laboratory environment to that of the organism’s natural environment. In 1912, Just’s first paper, “The Relation of the First Cleavage Plane to the Entrance Point of the Sperm.” was published in the Biological Bulletin. Just showed that eggs of the marine worm (Nereis) cleave in different planes depending on the sperm’s point of entry. To Just, the egg’s surface was an important and robust factor in the fertilization process. By showing that sperm had an equal probability of entering the egg at any point on the egg’s surface, and that the direction of cleavage depended on the arbitrary point of entry of sperm, and not some predetermined cleavage plane, Just made a dent in preformationist theory. It was also during this time that he married Ethel Highwarden in 1912 and met Jacques Loeb while Loeb was at the Rockefeller Institute for Medical Research. Similar research interests and Loeb’s stand on social equality made the two embryologists fast, but not longstanding friends. In 1915 Just was the first to receive the Spingarn Medal, presented annually to the African-American who performs the greatest service to his or her race. This was followed by the University of Chicago awarding Just his PhD degree in experimental embryology in 1916.
During 1919 and 1920, Just published four papers in the Biological Bulletin, all focusing on his work with the sand dollar Echinarachnius parma. In one set of experiments Just measured the elevation of the egg membrane at sperm contact and the time that it took for the membrane to be penetrated by a sperm. He observed that the sperm was pulled into the egg rather than the commonly held view that it actively bored its way into the egg. Just also documented a “wave of instability” that moved from the sperm’s entry point to the opposite side of the egg. Since then, embryologists have proven that such an instability wave is a wave of cortical granule exocytosis that forms the fertilization envelope. Just also saw that the wave was associated with an immediate blocking of any further sperm penetrability of the egg.
In 1920, while continuing to teach at Howard, Just obtained a ten-year research fellowship from Julius Rosenwald through the National Research Council. He wasted no time in returning to his work at Woods Hole where he continued to study the process of fertilization with results that strengthened Lillie’s work and questioned Loeb’s idea of “superficial cytolysis.” According to Loeb’s studies, egg development could be initiated by exposing eggs to butyric acid. Development was then immediately followed by the release of lysine, Loeb’s cytolytic agent, to break down the egg cortex. Just showed that putting eggs in butyric acid for a short period of time actually slowed cytolysis rather than sped it up. Just was able to prove that the cytolytic effect of the butyric acid was due to overexposure of the eggs to the acid and nothing more. He went even further in dismissing Loeb’s experimental findings on artificial parthenogenesis, attacking Loeb’s method of record-keeping and his apparent failure to maintain experimental conditions to mimic his experimental organisms’ natural environments.
The friendship that Just and Loeb had forged together at Woods Hole quickly vanished. Their disagreements played out for many years, with Loeb providing negative evaluations of Just to the Rockefeller Institute and the Carnegie Foundation. Every time Just tried to obtain grant money, Loeb’s evaluations seemed to rise up and quell any grant award.
In 1929 Just made his first trip to Europe and worked at Anton Dohrn’s Stazione Zoologica in Naples. For six months he experimented with sea urchins (Paracentrotus lividus and Echinus microtuberculatus) to see how these organisms develop and to continue testing Lillie’s “fertilizin” theory of fertilization. Around 1906 Lillie had hypothesized that eggs release a substance that he coined fertilizin. Upon contact with spermatozoa, said Lillie, fertilizin causes sperm to attach to it. Lillie believed that fertilizin molecules served as receptors on the egg’s surface. With receptors for egg and sperm surfaces, the molecule helped to “agglutinate” egg and sperm together.
In 1930 Just was invited to the Kaiser Wilhelm Institute in Berlin where he continued his studies of the ectoplasm with other species, including Amoeba. Just strove to show the importance of ectoplasm in initiation of development. While in Europe he published three articles on the role of ectoplasm: “ Die Rolle des kortikalen Cytoplasmas bei vitalen Erscheinungen” (“The Role of Cortical Cytoplasmin Vital Phenomena”) in Naturwissenschaften (1931) and “On Origin of Mutations” (1932) and “Cortical Cytoplasm and Evolution” (1933), both published in the American Naturalist. All three articles pointed to Just’s view that ectoplasm is necessary for fertilization to occur.
With little hope of ever being able to teach anywhere but a black college, and his continued failure to secure research funds, Just went to Europe in 1938 with the intent of leaving Howard and finishing out his research career on a new continent. In 1939 he published two books: Basic Methods for Experiments on Eggs of Marine Animals and The Biology of the Cell Surface. Both books reflected Just’s holistic view of eggs and embryos: that is, eggs are to be taken seriously in their own right rather than seen simply as tools to manipulate in order to prove a theory. While Just’s experiments may have been simple, he was an intense perfectionist when it came to laboratory procedure. His ability to keep laboratory environments similar to actual marine environments aided in the integrity of his research. It also led to his life-long criticism of experimental embryologists who failed to appreciate his tacit knowledge about inducing marine invertebrate reproduction. To Just, too many embryologists were busy taking eggs out of natural environments and subjecting them to unnatural manipulations while ignoring the importance of the eggs’ environment as an important factor in development. In The Biology of the Cell Surface, Just also continued his attack on the role of genes in development. He remained adamant that cytoplasm was the key to development and not the nucleus. This countered the growing enthusiasm by geneticists who held the idea that the nucleus controlled fertilization and development.
The Nazi invasion of France in 1940 forced Just to return to the US and Howard University, one of the few institutions at the time that would hire a black scientist. His attempt to recareer again in the United States was short-lived however. Just died of pancreatic cancer on 27 October 1941.
- Byrnes, Malcolm W. “Ernest Everett Just.” New Dictionary of Scientific Biography 4: 66– 70.
- Byrnes, Malcolm W., and William R. Eckberg. “Ernest Everett Just (1883-1941): An Early Ecological Developmental Biologist,” Developmental Biology 296 (2006): 1– 11.
- Gilbert, Scott F. “Cellular Politics: Ernest Everett Just, Richard B. Goldschmidt, and the Attempt to Reconcile Embryology and Genetics.” In The American Development of Biology, eds. Ronald Rainger, Keith R. Benson, and Jane Maienschein, 311–42. Philadelphia, PA: University of Pennsylvania Press, 1988.
- Gould, Stephen Jay. “Just in the Middle: A Solution to the Mechanist-Vitalist Controversy.” In The Flamingo’s Smile: Reflections in Natural History, 337-391. New York: W. W. Norton, 1985.
- Just, Ernest E., “The Relation of the First Cleavage Plane at the Entrance Point of the Sperm,” Biological Bulletin 22 (1912): 239–52.
- Lillie, Frank R. “Obituary of Ernest Everett,” Science 95 (1942): 10–11.
- Manning, Kenneth J. Black Apollo of Science: The Life of Ernest Everett Just. New York: Oxford University Press, 1983.
- Pauly, Philip J. Controlling Life: Jacques Loeb and the Engineering Ideal in Biology. New York: Oxford University Press, 1987.
Ernest Everett Just was an early twentieth century American experimental embryologist involved in research at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, and the Stazione Zoologica in Naples, Italy. Just was known for simple but elegant experiments that supported the "fertilizing" theory of Frank R. Lillie and served as an antagonist to Jacques Loeb's work with artificial parthenogenesis.Created: 2010-06-16
James David Ebert studied the developmental processes of chicks and of viruses in the US during the twentieth century. He also helped build and grow many research institutions, such as the Department of Embryology in the Carnegie Institution of Washington in Baltimore, Maryland and the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts. When few biologists studied the biochemistry of embryos, Ebert built programs and courses around the foci of biochemistry and genetics, especially with regards to embryology. He eventually directed the MBL's Embryology Course, and later, the MBL itself.
Ebert was born on 11 December 1921 in the town of Bentleyville, Pennsylvania. He attended public schools while growing up and then graduated from Washington and Jefferson College in Washington, Pennsylvania in 1942. Not long after graduation he joined the United States Navy and eventually became a lieutenant. Ebert was stationed on a destroyer in the Pacific Ocean that was attacked by a kamikaze pilot. The destroyer sank and Ebert spent twenty-four hours in the ocean until being rescued. Afterwards, as a biologist, Ebert befriended and trained several Japanese developmental biologists.
In 1946 Ebert began working towards his PhD in developmental biology under the instruction of Benjamin Willier at the Johns Hopkins University in Baltimore, Maryland. In the same year he married Alma Goodwin, who was a Women Accepted for Volunteer Emergency during the war. Ebert received his PhD in 1950 and immediately became a member of the faculty at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. After one year at MIT, Ebert moved to Indiana University in Bloomington, Indiana. Ebert became an associate professor of zoology by 1955, and he had started a program of experimental embryology. He studied chick embryos and the processes by which the protein make-up of the embryos changed throughout development.
Six years after receiving his PhD, Ebert became the director of the Carnegie Institution of Washington's Department of Embryology, in Baltimore, Maryland. Prior to Ebert's term as director, the department had had three other directors. The Institution's president, Caryl Haskins, had contemplated closing the department and starting something new. However, with some persuasion from Willier, Haskins spoke with Ebert and decided to give him the opportunity to run the department. Ebert and Haskins agreed that the department needed to focus on the study of genes and their regulation as well as the ways cells influence one another. Haskins said that Ebert's youth and enthusiastic personality made Haskins believe that Ebert would provide a fresh perspective to the department.
Ebert argued that it was his job to recognize and to recruit new talent and then support them in their work. He stressed the use of biochemistry and genetics, which in the 1960s blended together to form molecular biology. During this time, Ebert started to study the relationship between muscle cell differentiation and the propensity to infection in the Rous sarcoma virus.
While still director of the Carnegie embryology department, in 1970 Ebert also became the president and nonresident director of the Marine Biological Laboratory (MBL) at Woods Hole. At the MBL he researched, with Keiko Ozato, the response of murine lymphocytes to mitogens.
In 1977 Ebert ended his term at the Carnegie Department of Embryology, but he remained the director of the MBL. From 1978 until 1987, Ebert lived in Washington, D.C., and he was the president of the whole Carnegie Institution of Washington. As the institution's president, he made the decision to help build a large optical telescope in Chile at Las Campanas Observatory, and he worked towards the creation of a common campus for both Carnegie departments in Washington.
Ebert remained involved with scientific institutions for the rest of his life. When leaving one institution, he found another one to join. He retired from the Carnegie Institution in 1987 and became the president of the Chesapeake Bay Institute at the Johns Hopkins University, where he was a professor of biology for six years. Ebert was elected to many societies including the National Academy of Sciences, the American Philosophical Society, the American Academy of Arts and Sciences, and the Institute of Medicine. He was the vice president of the National Academy of Sciences from 1981 through 1993 and he also chaired its Government-University-Industry Research Roundtable from 1987 through 1993. His colleagues elected him as president of the Society for the Study of Development and Growth, the American Institute of Biological Sciences, and the American Society of Zoologists.
In retirement, Ebert and his wife Alma spent half of each year in Woods Hole and at the MBL. Ebert and Alma died on 22 May 2001 in an automobile accident while en route to Woods Hole.
- DeHaan, Robert L., and James D. Ebert. "Morphogenesis." Annual Review of Physiology 26 (1964): 15–46.
- Ebert, James D. "An analysis of the effects of anti-organ sera on the development, in vitro, of the early chick blastoderm." Journal of Experimental Zoology 115 (1950): 351–77.
- Ebert, James D. "An analysis of the synthesis and distribution of the contractile protein, myosin, in the development of the heart." Proceedings of the National Academy of Sciences 39 (1953): 333–44.
- Ebert, James D. "The effects of chorioallantoic transplants of adult chicken tissues on homologous tissues of the host chick embryo." Proceedings of the National Academy of Sciences 40 (1954): 337–47.
- Ebert, James D. "The formation of muscle and muscle-like elements in the chorioallantoic membrane following inoculation of a mixture of cardiac microsomes and Rous sarcoma virus." Journal of Experimental Zoology 142 (1959): 587–621.
- Ebert, James D., and Ian M. Sussex. Interacting Systems in Development. New York: Holt, Rinehart and Winston, 1970.
- Ebert, James D., and Fred H. Wilt. "Animal Viruses and Embryos." The Quarterly Review of Biology 35 (1960): 261–312.
- Obituaries. "Jim and Alma Ebert." Marine Biological Laboratory. http://www.mbl.edu/news/obit/obit_ebert.html (Accessed December 8, 2007).
- Ozato, Keiko, William H. Adler, and James D. Ebert. "Synergism of bacterial lipopolysaccharides and concanavalin A in the activation of thymic lymphocytes." Cellular Immunology 17 (1975): 532–41.
- Singer, Maxine. "James David Ebert." Proceedings of the American Philosophical Society 148 (2004): 124–27.
James David Ebert studied the developmental processes of chicks and of viruses in the US during the twentieth century. He also helped build and grow many research institutions, such as the Department of Embryology in the Carnegie Institution of Washington in Baltimore, Maryland and the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts. When few biologists studied the biochemistry of embryos, Ebert built programs and courses around the foci of biochemistry and genetics, especially with regards to embryology.Created: 2008-09-12
Jane Maienschein is the daughter of Joyce Kylander and Fred Maienschein, and was born in Oak Ridge, Tennessee, on 23 September 1950. She attended MIT as a freshman and then transferred to Yale University in 1969 when Yale decided to admit women undergraduates. In 1972 she graduated with an honors degree in History, the Arts, and Letters having written a thesis on the history of science. She then attended Indiana University and studied with historian of embryology Frederick B. Churchill, took courses with embryologist Rudolf Raff, and learned how to do embryological laboratory research with Robert Briggs. She received her MA in 1976 and a PhD in 1978, with a pre-doctoral Fellowship at the Smithsonian to study the history of microscopes and microscopy, and an NSF-funded dissertation improvement visit to the Marine Biological Laboratory (MBL) to reproduce old embryological experiments and soak up the history and resources of the MBL Library and labs. Maienschein’s scholarly research focuses on the history and philosophy of developmental biology.
In graduate school Briggs helped Maienschein reproduce historical experiments using the dissertation study of Ross Granville Harrison’s 1907 experiments on nerve fiber development. Harrison had asked whether the neuroblast cell (which we would now call a neural stem cell) can reach out and develop its fiber by protoplasmic outgrowth or whether the cell required a pre-established bridge, as many of his contemporaries argued must be the case. Harrison carried out the first ever tissue culture experiment, in which he got the neuroblast cells to grow when transplanted into an artificial medium of frog lymph. Briggs and Maienschein discovered that carrying out the experiment with the techniques Harrison described led to lots of nice bacterial and other unidentified cultures, but not nerve cells. Retracing Harrison’s steps revealed that he had taken advantage of being temporarily housed near the bacteriologists at Yale University and had used more sophisticated aseptic techniques than he described.
This work led Maienschein to an analysis of the role of the details of scientific practices and the value of carrying out “practical history,” as Edwin Clarke called it. She has also asked questions about the role of experiments in settling (or failing to settle) issues of theoretical debate. Her work in history of embryology has concentrated especially on the late nineteenth and into the twentieth century, including work done at the Marine Biological Laboratory in Woods Hole, Massachusetts, and on issues of morphogenesis and differentiation related to cell division. This research has led her to study stem cell research and regenerative medicine.
Maienschein is also a dedicated teacher who has received multiple awards, including the Arizona State University Parents Association Professor of the Year Chair, Regents’ Professorship, and President’s Professorship. In addition, she received the History of Science Society’s Joseph H. Hazen Education Prize Award. During the 105th United States Congressional session, in 1997 and 1998, she served as senior science advisor to Congressman Matt Salmon, who served on the Science Committee. She took a group of undergraduates to Washington, which led to their paper presentation at the 150th meeting of the American Association for the Advancement of Science, and that led to an invitation to write an editorial for Science. The students’ essay on “Scientific Literacy” remains the only publication in Science by undergraduates, and it led to a longer peer-reviewed article in Science Communication.
This personal exposure to the political context of science also led Maienschein to research reflecting more seriously on the social, political, and legal contexts of scientific research. Most productively, this has resulted in collaborative publications and projects with bioethicist Jason Scott Robert and Rachel Ankeny.
Maienschein served as the first president for the International Society for History, Philosophy, and Social Studies of Biology (“Ishkabibble”) in 1989–1991, president of the History of Science Society in 2008 and 2009, and in numerous other administrative rolls. She is Director of the Embryo Project, along with Manfred Laubichler.
- Arizona State University. http://www.public.asu.edu/~atjvm/ (Accessed October 24, 2008).
- Arizona State University Libraries. http://knet.asu.edu/research/?getObject=asulib:41285 (Accessed October 24, 2008).
- School of Life Sciences, Arizona State University. http://sols.asu.edu/people/faculty/jmaienschein.php (Accessed October 24, 2008).
Jane Maienschein is the daughter of Joyce Kylander and Fred Maienschein, and was born in Oak Ridge, Tennessee, on 23 September 1950. She attended MIT as a freshman and then transferred to Yale University in 1969 when Yale decided to admit women undergraduates. In 1972 she graduated with an honors degree in History, the Arts, and Letters having written a thesis on the history of science. She then attended Indiana University and studied with historian of embryology Frederick B.Created: 2008-10-24
Charles Otis Whitman was an extremely curious and driven researcher who was not content to limit himself to one field of expertise. Among the fields of study to which he made significant contributions were: embryology; morphology, or the form of living organisms and the relationships between their structures; natural history; and behavior. Whitman served as director of several programs and institutions, including the Biology Department at the University of Chicago, where he helped establish a new style of biology and influenced the work of many researchers of his generation, as well as future ones. He also served as first director of the Marine Biological Laboratory (MBL) in Woods Hole, MA. Besides his considerable achievements with his own scientific research, Whitman was a tireless mentor who had many students who went on to achieve great success in the field of embryology.
Whitman was born in North Woodstock, Maine, to parents Marcia and Joseph Whitman on 14 December 1842. He grew up on a farm and developed an interest in natural history, particularly that of pigeons, at an early age. Whitman’s family was typical of the rural area where he grew up, and he was educated in the public school system, but despite his family’s lack of money he was highly motivated to receive a college education. Whitman earned money by teaching and tutoring in private schools, and in 1865 he began attending Bowdoin College in Brunswick, Maine. Whitman was enrolled in the accelerated program and finished his degree in 3 years, graduating in 1868 with a BA. After graduation from Bowdoin College, Whitman took a position as Principal of Westford Academy in Massachusetts, where he remained for four years. He then moved to Boston to accept a position as instructor in natural science at English High School. This move was one of great importance, as it was in Boston that he became aware of Harvard University Professor of Zoology Louis Agassiz and enrolled to become one of fifty participants in the first session of the summer marine biology program at the Anderson School of Natural History on Penikese Island in 1873. This experience had a profound impact on Whitman as well as on other of Agassiz’s students. In 1874 Whitman joined the Boston Society of Natural History and, after a second summer at Penikese, he decided to dedicate himself to the full-time study of zoology.
In 1875 Whitman went to study in Europe under Anton Dohrn at the Stazione Zoologica in Naples. After working with Dohrn in Naples, Whitman and his fellow Penikese Island student Charles Sedgwick Minot moved to Leipzig, Germany. There, under the direction of parasitologist Rudolf Leuckart, he learned the modern methods of embryology and microscopy. Whitman received his PhD from the University of Leipzig in 1878. His dissertation was “The Embryology of Clepsine (glossiphonia)”, with an emphasis on the direct role of cleavage in histogenesis, or the differentiation of cells into specialized tissue and organs during growth. This research was instrumental in laying the groundwork for future studies of cell lineage. Whitman found evidence that leech egg development was completely predetermined. This finding supported the regulative theory of embryo development, according to which the whole embryo regulates the development of each cell, in contrast to the mosaic theory in which each cell develops independently, like a mosaic tile. His discoveries while working with the leech were instrumental to future taxonomical and morphological studies.
In 1879 he was offered a postdoctoral fellowship at the Johns Hopkins University but turned it down when he was invited to become Professor of Zoology at the Imperial University of Tokyo. He only spent two years there, but his short tenure was extremely influential. Eight of Whitman’s students there went on to become prominent zoologists, including four who held major chairs, affording him the informal title “father of zoology” in Japan. From November 1881 until May 1882, Whitman returned to the Stazione Zoologica to study the embryology, life history, and classification of the dicyemids which led to the publication of a standard reference work on the parasite in 1883. From 1882 through 1886 Whitman worked as an assistant to Alexander Agassiz at the Museum of Comparative Zoology at Harvard University. During this time Whitman also served as the editor for the Department of Microscopy at the American Naturalist Magazine. After Harvard, Whitman took the job of tutoring amateur zoologist Edward Phelps Allis, Jr., in Milwaukee, Wisconsin. In addition to tutoring Allis, he took on the task of directing the very short lived Allis Lake Laboratory. While there, Whitman oversaw the work of many researchers, including William Morton Wheeler, who went on to become a prominent figure in the study of social insects.
During the summer of 1888 Whitman was invited to direct the newly established Marine Biological Laboratory in Woods Hole, a position he held until 1908. In 1889 Whitman left the Allis Lake facility to take the position of Chair of Zoology at Clark University in Worcester, Massachusetts. In 1892 Whitman moved again to become head of the biology department at the newly founded University of Chicago. There Whitman had several students who went on to make names for themselves in embryology. One of the most prominent was Frank Rattray Lillie, who took over as director at the MBL after Whitman and succeeded Whitman at the University of Chicago, as well. Whitman had many embryologist colleagues at Chicago, including Frank Rattray Lillie, Jacques Loeb, Franklin Paine Mall, Albert Davis Mead, Shosaburo Watase, and William Morton Wheeler. Whitman remained at the University of Chicago until his death on 6 December 1910.
Whitman’s study of sexual dimorphism, the morphological differences between male and female organisms of the same species, was an influence on Oscar Riddle and his endocrinological research. Whitman’s 1898 paper “Animal Behavior” contains many examples of innate, non-learned, behavior. In his later work, he analyzed the relation between innate and learned behavior and the ability of animals to adjust their behavior to new experiences. Whitman saw a similarity of variation in related species, and the trends of evolutionary change in all species from the simplest of organisms to the most advanced. In 1900, when researchers were torn between the theories of mutation and selection, Whitman was a strong proponent of selection.
Whitman published papers and journal articles on every aspect of his work, but is probably best known for his posthumously published three-volume work The Orthogenic Evolution in Pigeons, considered to be the first extensive study in comparative ethology. Whitman was instrumental in the founding of several journals and academic institutions, including the Journal of Morphology, the Biological Bulletin, and the American Morphological Society which, through a merger with the Western Branch of the American Society of Naturalists (known as the Society of American Zoologists in 1901 and 1902), became the American Society of Zoologists in 1902.
Whitman’s work significantly impacted the field of embryology. It greatly influenced the researchers of his generation as well as future generations. Whitman made significant contributions in the fields of embryology, morphology, taxonomy, and ethology. He published numerous books and papers in all of these subjects. Whitman was a mentor to biology students in several institutions around the world. Many of the institutions and publications he founded continue to be at the top of the field of embryology today.
- Carr, Harvey A., and Oscar Riddle, eds. Posthumous Works of Charles Otis Whitman. Vol. I–III. Washington DC: Carnegie Institution of Washington, 1919.
- Davenport, Charles B. “The Personality, Heredity and Work of Charles Otis Whitman.” American Naturalist 51 (1917): 5–30.
- Gilbert, Scott. Developmental Biology, 7th ed. Sunderland, MA: Sinauer Associates Inc., 2003.
- Mayr, Ernst. “Whitman, Charles Otis.” Dictionary of Scientific Biography 13: 313–15.
- Newman, Horatio Hackett. “History of the Department of Zoology in the University of Chicago.” Bios 19 (1948): 215–39.
- Pauly, Philip J. “From Adventism to Biology—the Development of Whitman, Charles Otis.” Perspectives in Biology and Medicine 37 (Spring 1994): 395–408.
Charles Otis Whitman was an extremely curious and driven researcher who was not content to limit himself to one field of expertise. Among the fields of study to which he made significant contributions were: embryology; morphology, or the form of living organisms and the relationships between their structures; natural history; and behavior.Created: 2009-01-21
The Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, began in 1888 to offer opportunities for instruction and research in biological topics. For the first few years, this meant that individual investigators had a small lab space upstairs in the one wooden building on campus where students heard their lectures and did their research in a common area downstairs. The lectures for those first years offered an overview of general biology with a focus on zoology, and they were intended for teachers and graduate students interested in acquiring the background for teaching about and/or actually doing laboratory work. As the lab quickly grew, it added sets of lectures that made up courses in zoology, then botany, then physiology, and in 1893 what became the first Embryology Course.
The 1890s were a lively time in embryology, with new techniques and discoveries related to the roles of cells in development, and a growing excitement about the way that experimental embryological manipulations could reveal processes that otherwise remain inside the usually opaque embryo. The MBL recognized the importance of this work and began their course in embryology, which was offered as an elementary course in vertebrate embryology. This was designed for those who had already had the general course, and it had the appeal of offering something more advanced that would bring students back for an additional year. The goal that first year was to allow students to discover the details of development, and to learn the methods for doing the work. The six-week course was directed by Charles Otis Whitman, who was the MBL director, and his student and protégé Frank Rattray Lillie, who became Whitman’s Assistant Director and then his successor as Director both at the MBL and also at the Biology Department at the University of Chicago.
Students were expected to bring their own equipment, including a compound microscope, a dissecting microscope (and it was specified that the Paul Meyer pattern made by Zeiss was the best of the kind), a camera lucida , microtome, and other standard embryological equipment to make up a “complete outfit.” Each student was given a supply of fish eggs and expected to follow the stages of development starting with fertilization. The camera lucida was to facilitate drawing, which was an important part of embryological work until relatively recently. The students all learned the most up-to-date techniques for observing, preserving, embedding, fixing, staining, and then drawing, reconstructing, and modeling embryological processes. The course cost fifty dollars for a number of years and was limited to a dozen students.
For the second year, students were required to have not just a general biology course but also an anatomy course as a pre-requisite. The course continued until 1901, when the lab had grown enough that the course expanded its staff and added zoology as a pre-requisite. The goal of the course was not just to teach the basics of embryology but also to prepare students to take up independent investigations of their own. In addition, the course announcements emphasized the value of studying such a subject at the MBL. Here it was not necessary to rely on preserved developmental stages fixed to slides, but it was possible also to study the living material available during a summer at the seashore. The course continued, with new directors and instructors and with students going on to their own research and sometimes returning as instructors themselves.
Only in 1921 did the course begin to cost seventy-five dollars. Hubert Goodrich became director in 1922 and remained so until 1942. This was an important time for embryology, and the course clearly offered the basics in experimental techniques and introduction to modern theory. It probably served as a very valuable introduction for many young scientists, who encountered living material, interacted with established researchers, and learned how to use equipment and techniques not just to see what others had reported before but also how to ask new questions and prod the embryos to yield answers.
1942 brought a continuation of the basic approach but also a new director. Viktor Hamburger had served as an instructor (view PDF [10.1 MB] of original Hamburger lecture notes) since 1937, shortly after he had taken his experience in Hans Spemann’s lab in Germany to the University of Chicago. There, Lillie undoubtedly lured him to the MBL for the summer and put him to work. Hamburger directed the Embryology Course from 1942 through 1945, when long-time instructor, Donald Costello from the University of North Carolina, took over through 1950. Where Hamburger looked at neuroembryology in his own work and emphasized patterns of development and causes of differentiation, Costello was especially interested in comparative invertebrate embryology. No doubt their approaches worked together well, and the course retained its flavor of lab research drawing on the natural history of the marine offerings.
In the 1950s S. Meryl Rose from the University of Illinois and then Mac V. Edds from Brown University directed the course. This is a period when such notables as John Tyler Bonner of Princeton University, with his enthusiasm for slime molds and problems of morphogenesis, John P. Trinkaus (known as Trink), Clifford Grobstein from the National Cancer Center, Philip Grant from Johns Hopkins University, John W. Saunders from Marquette University, and others brought new perspectives to the traditional course. Throughout this period and dating back to the 1940s, they listed a set of books that students should have, and the list remained surprisingly constant in ways that would be unlikely in this rapidly changing field today.
In 1962 James Ebert at the Carnegie Institution of Washington became director and things changed. The course description shifted for the next year, and the course fee rose to $300—$150 for the series of lectures plus $150 for those who wished to stay for an additional period of individual investigation. The course was becoming less introductory and more designed for would-be researchers such as graduate students and post-doctoral fellows who wanted to learn advanced techniques and to hear about theories and problems in development. The content remained, with additions of Ebert’s specialty work in organogenesis, but Ebert’s five year run as course director made the course at least look more professional in its focus on modern technical topics. This move to professionalism was reinforced by NIH training grants that supported the Embryology and sometimes other courses in the late 1960s and beyond.
In 1971 the course fees rose to $400 + $400, and the announcement made clear that the course was targeted to graduate students and post-doctoral fellows, and to advanced undergraduates seriously interested in pursuing research in this field. Also in 1971, Eric Davidson from Cal Tech served as an instructor. In 1972 he became course director and served in that role through 1974, then again from 1988 through 1996, making him the longest-running course director and giving him the opportunity for the greatest impact on the history of the course. He took great advantage of the opportunity to revise and update the course. In fact, Davidson brought the first major changes in the course which was now “centered around one particular conceptual area of developmental biology.” And the emphasis clearly shifted from instruction and introduction to research to a higher level of expected training and investment in research on the part of the participants.
The focus for 1972 was cytoplasmic localization phenomena, for 1973 the synthesis, storage, and utilization of developmental genetic information during oogenesis in vertebrates and invertebrates, and in 1974 “Sequence Organization in the animal genome and transcription-level gene regulation.” This was a significant shift, and arguably Ebert and Davidson in their different ways had done the most to move the traditional popular course into the professional and molecular era of the late twentieth century.
David Epel from the University of California at San Diego brought an emphasis on cells and cell-cell communication with “Cell Interactions, Cell Membranes, and Cell Surfaces in Development” (1975). Then Tom Humphreys from the University of Hawaii joined Epel in offering “Developmental Regulation of Gene Expression” (1976), “Extracellular Signals in Cell Growth and Differentiation” (1977), and “Localization, Pattern Formation, and Morphogenesis” (1978 and 1979). Rudolf Raff from Indiana University directed “The Control of Events in Early Embryology Development” (1980), “Gene Control and the Events of Early Embryonic Development” (1981), and “Cytoplasmic Localization, Determination, and Gene Control in Development” (1982). These years brought a much expanded list of instructors and lecturers, as the field became more complex and it was important to bring together speakers across the wide range of new ideas and techniques.
Then in 1984, under the direction of William Jeffery from the University of Texas at Austin and Bruce Brandhorst from McGill University, the course reverted to the simpler title of “Embryology: A Modern Course in Developmental Biology.” From 1989 through 1996 the title was “Embryology: Cell Differentiation and Gene Expression in Early Development” and from 1997 to present, it has been “Embryology: Concepts and Techniques in Modern Developmental Biology.”
Discussions by the Education Committee and course directors at various points show that the MBL considered whether to change the name to reflect more current thinking, namely with an emphasis on developmental biology and an emphasis on molecular genetics rather than the traditional embryology. They decided to stick with the traditional course that is now more than one hundred and fifteen years old and instead added other January short courses focused on developmental and molecular techniques. Of course the Embryology course, taught in traditional labs, includes a considerable dose of modern molecular work. And students in recent years admit that they no longer go out to muck about and collect specimens themselves, nor do they have any idea where to look in most cases. Yet there is a tie to tradition, to the observations and collections of the past century, and course instructors will send their students to the MBL Rare Books Room to discover something of the history and context of the work that is now so different from and yet so grounded in the traditions of its predecessors.
View a timeline of the directors and instructors here.
- Marine Biological Laboratory Annual Announcements: MBL-WHOI Library Special Collections.
- Marine Biological Laboratory Annual Reports: available in the MBL The Biological Bulletin Vols. 17 and 21–105 at http://www.archive.org/details/biologicalbullet01mari and beginning with 2004 at http://www.mbl.edu/governance/gov_annual_report.html.
The Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, began in 1888 to offer opportunities for instruction and research in biological topics. For the first few years, this meant that individual investigators had a small lab space upstairs in the one wooden building on campus where students heard their lectures and did their research in a common area downstairs.Created: 2007-10-24
Frank R. Lillie was born in Toronto, Canada, on 27 June 1870. His mother was Emily Ann Rattray and his father was George Waddell Little, an accountant and co-owner of a wholesale drug company. While in high school Lillie took up interests in entomology and paleontology but went to the University of Toronto with the aim of studying ministry. He slowly became disillusioned with this career choice and decided to major in the natural sciences. It was during his senior year that he developed his lifelong interest in embryology. Graduating with a BA in 1891 Lillie then moved to the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, to work and study with Charles Otis Whitman, the founding director of the MBL. Lillie collected and studied cell lineage side-by-side with some of the most prominent embryologists of the time: Edmund B. Wilson, Edwin G. Conklin, and Aaron L. Treadwell. Along with his cell lineage studies, Whitman guided Lillie to work on the question of how blastomeres contributed to the formation of organs in fresh water clams.
In 1892 Lillie followed Whitman to the University of Chicago zoology department where Whitman had accepted a chair appointment. In 1894 Lillie graduated with a PhD in zoology. His dissertation was a descriptive study of cell lineage in freshwater mussels. From 1894 through 1899 Lillie worked as an instructor at the University of Michigan. In 1895 he married Frances Crane, sister of Chicago businessman Charles R. Crane. His brother-in-law would soon play a large role in introducing Lillie to the social elite in Chicago and helping to expand the MBL campus. During his marriage Lillie and his wife had five daughters, one son, and three adopted sons. Lillie briefly taught biology in upstate New York at Vassar College before returning to the University of Chicago as an assistant professor of embryology. In 1902 he was made an associate professor followed by a full professor in 1906. In 1908 Lillie published his classic book on chicken embryology, Development of the Chick: An Introduction to Embryology. Along with writing the text, Lillie prepared a large series of serial sections of the chick embryo at various stages to serve as illustrations. With revisions, the text and laboratory manual continue to be used to the present time, serving as one of the best accounts available on bird development.
In 1910 Lillie was made chair of the Department of Zoology. During this time he united the embryology program with the rest of the zoology department. With the combining of the departments, the budgets were also combined and Lillie was able to use his influence to obtain more money for embryological research. In 1931 Lillie was appointed dean of the Division of Biological Sciences at Chicago. After many years of distinguished teaching and research he was made the Andrew MacLeish Distinguished Service Professor of Embryology and the dean of biological sciences. In 1935 he was given emeritus professor status.
Although rarely written about, Lillie was a member of Chicago’s Eugenics Education Society, a committee member of the Second International Eugenics Congress, and served on the advisory council for the Eugenics Committee of the United States. In the early 1920s Lillie envisioned an Institute of Genetic Biology that would gather data to examine population problems, public health, and social control, but this never came to fruition.
Lillie is probably best known for his leadership at the Marine Biological Laboratory at Woods Hole. He organized the MBL’s first course in embryology in 1893 and became course director the following year. At that time the MBL consisted of one small building, a few skiffs, and a dock. In 1902 funding for the laboratory was so great that the corporation and board of the MBL considered transferring the laboratory to the Carnegie Institution of Washington to make the MBL Carnegie’s permanent marine research laboratory. Lillie and Whitman opposed the transfer and convinced the board to reverse its offer to Carnegie. To this day the MBL remains a laboratory relatively free from layers of outside control.
From 1900 to 1942 Lillie worked tirelessly to improve the laboratories and accommodations for the myriad of scientists who descended on Woods Hole during the summer months. Lillie called upon his brother-in-law to help finance the expansion of the MBL and Crane served as president of the corporation from 1904 through 1924. The Crane laboratory at MBL was named after the man who financed its building. Lillie was instrumental in making the marine laboratory into one of the leading research laboratories in the world. Not only did he serve as president of the corporation from 1925 to 1942 but he also served as Managing Editor of the MBL’s scientific publication The Biological Bulletin for twenty-five years.
Lillie was an outstanding administrator and teacher but the depth of his research in embryology and development is also remarkable. His early research primarily dealt with egg cleavage and early development in invertebrates. Although his early cell lineage work was mainly descriptive and comparative, it helped lay the foundation for experimental studies by Wilhelm Roux in 1888 and Hans Driesch in 1891. Lillie heavily influenced his former student and noted embryologist Ernest E. Just to continue working with Nereis to show the relationship of egg cleavage planes to the entry point of sperm.
In 1903 and 1904 Lillie published several papers on his studies of the chick embryo. Included in the papers was discussion about the formation of the amnion and his experiments with cauterizing parts of the embryo to see how further development of parts of the embryo were affected. Lillie had always shown interest in the chick embryo. He was convinced that chick embryos were the best choice for almost any type of experimental work of embryological problems.
From 1910 to 1921 Lillie’s research centered on fertilization in the annelid Nereis limbata and sea urchins Arbacia punctulata and Strongylocentrotus franciscanus and S. purpuratus. Lillie proposed that there were specific substances (fertilizin and antifertilizin) secreted by egg and sperm. Part of Lillie’s “fertilizin theory” likened the interaction between gametes to that of the lock-and-key fashion of antibodies and antigens. This was notable in that Lillie applied the then current immunological concepts and terminology to that of fertilization.
Lillie’s investigation of the factors influencing the development of freemartins (sterile genetic female calves born as a twin to fertile male calves) helped Lillie answer the question of how sexually indifferent embryos at the beginning of development later turn into males or females. Beginning in 1914 Lillie worked with stockmen in the Swift and Company stockyard to obtain fifty-five pairs of in utero fetal twins from freshly slaughtered pregnant cows. In 1917 Lillie published his study in the Journal of Experimental Zoology with the finding that freemartin bovine twins are non-identical and that they share the same placenta, allowing for blood to be freely exchanged between the twin fetuses. A male’s testes form early in development and “masculinizing” substances (hormones) are released and circulate through the fused umbilical arteries. Lillie concluded that the freemartin was a genetic female calf that had certain male sexual characteristics due to the action of a fetal male sex hormone. This work led to the concept that once a gene directs a gonad to differentiate into a testes or an ovary, accessory reproductive structures in genetic males develop in the male direction due to the presence of male hormones. Genetic females develop rudimentary reproductive structures because they are not inhibited from developing due to a lack of male sex hormones. Lillie’s research with freemartins introduced the notion of the nature and action of sex hormones to embryologists when little was known about hormones. Soon, others at the University of Chicago attempted to produce freemartins in birds ( Benjamin Willier) and mammals ( Carl R. Moore). Castration experiments in fetal mammals in utero and research in the isolation and purification of sex hormones was undertaken in other laboratories at the University of Chicago. The subsequent work stemming from Lillie’s freemartin investigation helped form the field of reproductive biology.
Even after retiring from the University of Chicago in 1935, Lillie continued with his sex hormone studies by investigating the physiology and development of bird feathers. He used the Brown Leghorn fowl, a bird that displays a notable sexual dimorphism in feather color and patterns. He collaborated with Mary Juhn and His Wang to discover that embryonic feather papillae all start out with the same background color. Further feather coloration and patterns develop in an orderly fashion in response to both female sex hormones and thyroxin. Part of his research involved using castrated males into which injections of estrogens and thyroxin were given to induce “female” feather colorings in the birds’ regenerating feathers.
From 1935 to 1939 Lillie was president of the National Academy of Sciences and in 1935 to 1936 was chairman of the National Research Council. To date he is the only person ever to have held both leadership positions in the two organizations at the same time. Lillie was also appointed chairman of the National Academy of Sciences Oceanographic Committee to study the financing and construction of an Institute of Oceanography. In 1930 he helped secure a three million dollar grant from the Rockefeller Foundation to help locate and build the Oceanographic Institute next door to the MBL. Lillie served as president of the Woods Hole Oceanographic Institute from 1930 to 1939.
Lillie died of a stroke on 5 November 1947 in Billings Hospital at the University of Chicago, the campus at which his professional life had so intimately been connected. Thus ended the career of one of the world’s foremost embryologists and science administrators—a career that science historian Philip J. Pauly identified as having helped make biology the first science in which Americans became internationally recognized.
- Lillie, Frank R. The Problems of Fertilization. Chicago: University of Chicago Press, 1919.
- Manning, Kenneth J. Black Apollo of Science: The Life of Ernest Everett Just. New York, Oxford University Press, 1983.
- Mitman, Gregg. The State of Nature: Ecology, Community, and American Social Thought 1900–1950. Chicago: University of Chicago Press, 1992.
- Moore, Carl R. “Frank Rattray Lillie: 1870-1947.” Science 107 (1948): 33–35.
- Pauly, Philip J. Controlling Life: Jacques Loeb and the Engineering Ideal in Biology. New York: Oxford University Press, 1987.
- Watterson, Ray L. “The Striking Influence of the Leadership, Research, and Teaching of Frank R. Lillie (1870-1947).” American Zoologist 19 (1979): 1275–87.
- Willier, Benjamin. H., Ross G. Harrison, Henry. B. Bigelow, and Edwin. G. Conklin. “Addresses at the Lillie Memorial Meeting Woods Hole.” The Biological Bulletin 95 (1948): 151–62.
Frank R. Lillie was born in Toronto, Canada, on 27 June 1870. His mother was Emily Ann Rattray and his father was George Waddell Little, an accountant and co-owner of a wholesale drug company. While in high school Lillie took up interests in entomology and paleontology but went to the University of Toronto with the aim of studying ministry. He slowly became disillusioned with this career choice and decided to major in the natural sciences. It was during his senior year that he developed his lifelong interest in embryology.Created: 2009-07-22
Jacques Loeb experimented on embryos in Europe and the United States at the end of the nineteenth and beginning of the twentieth centuries. Among the first to study embryos through experimentation, Loeb helped found the new field of experimental embryology. Notably, Loeb showed scientists how to induce artificial parthenogenesis, thus refuting the idea that spermatozoa alone were necessary to develop eggs into embryos and confirming the idea that the chemical constitution of embryos’ environment affected their development. Furthermore, Loeb’s work showed that scientists could manipulate materials in a laboratory to create, as he called the process, the beginning stages of life.
Jacques Loeb was born in the Prussian town of Mayen to Barbara and Benedict Loeb in 1859. Named “Isaak,” he changed his name to “Jacques” just prior to entering the University of Strassburg in 1880. At Strassburg Loeb studied with the physiologist Friedrich Goltz and there he earned his MD in 1884.
Until 1891 Loeb taught and researched at various institutions, including the Naples Zoological Station in the winters of 1889 and 1890. In 1890 he met and married Anne Leonard, an American philologist. Moving to the United States, Loeb taught at Bryn Mawr College for a year prior to accepting an assistant professorship with the University of Chicago in 1892. While at Bryn Mawr Loeb met and initially disliked the young Thomas Hunt Morgan. At Chicago Loeb struggled to get along with Charles Otis Whitman, and to tolerate what Loeb termed the “romantic evolutionism” espoused most prominently by Chicago’s John Dewey.
After a decade at Chicago, Loeb moved to the University of California at Berkeley for eight years. In California he experimented at Stanford University’s Hopkins Marine Station in Pacific Grove. He then returned east to New York’s Rockefeller Institute for Medical Research in 1910, working there until he died in 1924. During his career, he conducted many of his experiments at Bryn Mawr, Chicago, Rockefeller, and at the Marine Biological Laboratory in Woods Hole, Massachusetts.
Loeb’s early work at Strassburg was on brain physiology. Having judged the field’s dominant theory misguided, he decided to instead study traditional issues in biology such as embryology. He used experiments to answer questions about development and embryology rather than observation alone, which was the common method of biological inquiry. Loeb looked to the scientific practices of physiologists Goltz, Eduard Pflüger, and the eminent plant physiologist Julius Sachs for methodological inspiration.
Loeb worked with Sachs extensively while the former worked at the University of Würzburg for two years starting in 1886. Loeb then developed a correspondence and friendship with the Austrian physicist and philosopher Ernst Mach, whose writings provided the theoretical foundation for Loeb’s work. For Loeb, any explanation of phenomena could come only from manipulating the physical structures of things and their chemical makeup. That conception of scientific knowledge, based on physicochemical manipulations, paralleled Wilhelm Roux’s mechanistic conception of science encapsulated in Entwicklungsmechanik.
Like Mach, Loeb thought science was not a mere description of nature but was instead a tool for humans to interact with nature. To him, a biologist was like an engineer and organisms were biologists’ material. Loeb earned his reputation as a biologist-engineer in 1899 when he published experimental results showing artificial parthenogenesis in sea urchins, in “ On the Nature of the Process of Fertilization and the Artificial Production of Normal Larvae (Plutei) from the Unfertilized Eggs of the Sea Urchin”.
Artificial parthenogenesis is the human manipulation of egg cells causing embryonic development without spermatozoa. Loeb manipulated unfertilized sea urchin eggs with inorganic solutions of salt water. The result was eggs developing into larvae, or early stage embryos, which he later reproduced using frog eggs. Loeb elaborated on his results in 1913’s Artificial Parthenogenesis and Fertilization.
Loeb’s 1899 results stirred the popular presses, and many viewed him as a creator of life, perhaps with the ability to engineer new types of organisms. Loeb was never able to create new forms of life, as he intended, but he inspired scientists such as John Howard Northrop, John Broadus Watson, Hermann Joseph Müller, Burrhus Frederic (B. F.) Skinner, and Gregory Pincus. Loeb also contributed to the study of animal tropisms (environment-caused orientation).
Loeb helped transform biology into a largely experimental science. His 1912 The Mechanistic Conception of Life established his reputation as a researcher who treated organisms as machines. In that work, he stated that biologists explain organic phenomena only when they could control those phenomena. Loeb later believed that biologists explain phenomena by detailing the mechanisms, the step-by-step processes, by which a component of an organism achieves its function in physical and chemical terms. In The Organism as a Whole (1916), Loeb discussed how a mechanist could investigate organisms considered as wholes. His commitment to physicochemical explanations led him to study protein chemistry for the last few years of his life. Loeb died in 1924.
- Loeb, Jacques. Artificial Parthenogenesis and Fertilization. Chicago: University of Chicago Press, 1913.
- Loeb, Jacques. “Mechanistic Science and Metaphysical Romance.” Yale Review 4 (1915): 766–85.
- Loeb, Jacques. “On the Nature of the Process of Fertilization and the Artificial Production of Normal Larvae (Plutei) from the Unfertilized Eggs of Sea Urchins.” The American Journal of Physiology 3 (1899): 135–38.
- Loeb, Jacques. The Organism as a Whole: From a Physicochemical Viewpoint. New York: G.P. Putnam’s Sons, 1916.
- Loeb, Jacques. The Mechanistic Conception of Life. Ed. Donald Fleming. Cambridge, Mass.: Harvard University Press, 1964.
- Pauly, Philip. Controlling Life: Jacques Loeb and the Engineering Ideal in Biology. New York: Oxford University Press, 1987.
Jacques Loeb experimented on embryos in Europe and the United States at the end of the nineteenth and beginning of the twentieth centuries. Among the first to study embryos through experimentation, Loeb helped found the new field of experimental embryology. Notably, Loeb showed scientists how to create artificial parthenogenesis, thus refuting the idea that spermatozoa alone were necessary to develop eggs into embryos and confirming the idea that the chemical constitution of embryos environment affected their development.Created: 2009-06-10