In 1951 Viktor Hamburger and Howard Hamilton published normal stages of chick embryogenesis that became a standard in the field and is still widely used today. “Ever since Aristotle ‘discovered’ the chick embryo,” they wrote, “as the ideal object for embryological studies, the embryos have been described in terms of the length of time for incubation, and this arbitrary method is still in general use…” (Howard and Hamilton 1951, p. 49). Hamburger and Hamilton recognized that the problem with staging embryos temporally was that the total length of development varied depending on factors such as breed or the temperature of incubation. Instead of using time intervals, they staged chick development based on morphological characteristics. This visual staging system, published as a series of micrographs and drawings of each stage, was critical for establishing the chick as an experimental model organism in the latter half of the 20th century.
Working out these stages required close study of the morphological details of chick embryos. Hamburger took detailed visual notes on parts of embryos that he ultimately used to stage them. For example, he closely studied the development of the limb buds, comparing and differentiating them based on subtle differences in shape. Hamburger also characterized the pharyngeal arches in embryos at various points in development. In his drawings, he followed their changing shape and created a labeling system for easy identification of each tissue fold. Many of these drawings were synthesized from observations of several embryos and were not direct representations of individual specimens.
Once they had a general idea of each stage, Hamburger and Hamilton generated images for their publication. This process involved finding embryos representative of each stage and then photographing them. Each specimen was photographed and printed several times to obtain a publishable shot that depicted important identifying features. In many cases, a photograph was paired with a simplified drawing to more clearly call attention to morphological details.
Seeing with Multiple Mediums
- Landecker, H. (2006). Microcinematography and the History of Science and Film. Isis, 97(1), 121–132. http://doi.org/10.1086/501105
- Brauckmann, S. (2011). Cultures of seeing embryos and cells in 3-dimensions and flatness. Studies in History and Philosophy of Biological and Biomedical Sciences, 42(4), 365–367. http://doi.org/10.1016/j.shpsc.2011.07.010
- Brauckmann, S. (2012). On Fate and Specification: Images and Models in Developmental Biology. In N. Anderson & M. R. Dietrich (Eds.), The Educated Eye: Visual Culture and Pedagogy in the Life Sciences (pp. 213–234). Dartmouth College Press.
- Maienschein, Jane. 1991. “From Presentation to Representation in E. B. Wilson’s The Cell.” Biology and Philosophy 6 (2): 227-54.
Staging Development
- Hamburger, Viktor and Howard L. Hamilton. (1951). “A Series of Normal Stages in the Development of the Chick Embryo.” Journal of Morphology 88(3): 49-92.
- Hopwood, N. (2005). Visual Standards and Disciplinary Change: Normal plates, Tables and Stages in Embryology. History of Science, 43, 239–303.
Looking at Cells
Wilson and Conklin: Tracing Cell Lineages
- Conklin, E. G. (1897). The Embryology of Crepidula: A Contribution to the Cell Lineage and Early Development of Some Marine Gasteropods. Journal of Morphology, 13(1), 1–226.
- B. Wilson, E. (1892). The cell-lineage of Nereis: A contribution to the cytogeny of the annelid body. Journal of Morphology, 6(3), 361–481.
Holtfreter: Observing Cells
- Holtfreter, Johannes. (1943). “A study of the mechanics of gastrulation Part I.” Journal of Experimental Zoology 94: 261-318.
- Holtfreter, Johannes. (1944). “A study of the mechanics of gastrulation Part II.” Journal of Experimental Zoology 95: 171-212.
- Hamburger, Viktor. (1996). “Introduction: Johannes Holtfreter, Pioneer in Experimental Embryology.” Developmental Dynamics 205: 214-216.
- Gerhart, John. (1998). “Johannes Holtfreter: January 9, 1901–November 13, 1992,” Biographical Memoirs National Academy of Sciences 73: 209–28.
Trinkaus: Filming Embryos
- Trinkaus, John Philip. "Surface activity and locomotion of Fundulus deep cells during blastula and gastrula stages." Developmental Biology 30 (1973): 68–103.
- Trinkaus, John Philip. "The yolk syncytial layer of Fundulus: Its origin and history and its significance for early embryogenesis." Journal of Experimental Zoology 265 (1993): 258–84.
Experimenting on Embryos
Exogastrulas
- Gerhart, John. (1998). “Johannes Holtfreter: January 9, 1901–November 13, 1992,” Biographical Memoirs National Academy of Sciences 73: 209–28.
Transplating Limb Buds
- Allen, Garland E. (2004). “A Pact with the Embryo: Viktor Hamburger, Holistic and Mechanistic Philosophy in the Development of Neuroembryology, 1927-1955.” Journal of the History of Biology 37: 421-474
- Hamburger, Viktor. (1934). ‘‘The Effects of Wing Bud Extirpation on the Development of the Central Nervous System in Chick Embryos.’’ Journal of Experimental Zoology 68: 449–494.
- Hamburger, Viktor. (1938). ‘‘Morphogenetic and Axial Self-differentiation of Transplanted Limb Primordia of Two-day Chick Embryos.’’ Journal of Experimental Zoology 77: 379–397
