the form of a footnote to Figure 23, with few interpreted 

 observations to interfere. 



To a certain extent, the report of Kazan University 

 Professor E. I. Eichwald (80), "Physiological investigations 

 of the Human Ova, "38 is considered a response to Pander. It 

 was preceded by an extensive introduction in the form of 

 a letter to Pander, in which Eichwald mentioned his studies 

 on embryology ("Observations of the Developing Chicken Egg") 

 performed in Petersburg under Pander's supervision. His 

 interest in embryology led him to the comparative study of 

 the ova of different animals and humans. His work contains 

 few original observations and indicates insufficient 

 acquaintance with the literature, but it has significance 

 in that Eichwald tried to apply a comparative embryological 

 method. He compared parts of the egg, especially the egg 

 membranes39 and provisory organs in different vertebrates 

 (lizards, bony fishes, amphibia, reptiles, birds and mammals, 

 and also in man) , and he even tried to compare the eggs and 

 embryos in vertebrates and invertebrates (insects, Crustacea 

 and worms) . On comparing the structures of eggs or ova of 

 different animals, Eichwald came to the conclusion that "if 

 the yolk in birds is, like that of quadrupeds, amphibia, fish, 

 crabs and insects, composed of numerous balls, then we can 

 presumbably conclude that the human ovum is composed of these 

 same balls" (p. 7). Later Eichwald wrote in detail about 

 the fact that all the layers of the blastoderm and the organs 

 of the embryo developing from them "gradually develop from 

 these primary balls, i.e. all the embryo from the beginning 

 is composed of a granular mass." Thus Eichwald anticipated 

 the cellular structure of the embryo, study of which became 

 widespread in embryology under the later influence of the 

 work of Remak, Reichert, Kolliker, and others. 



Pander's embryological investigations had some effect on 

 some of his countrymen working in entomology. Thus, a member 



38. Eduard Eichwald, "In ovum humanum disquisitio 

 physiologica, Casani," (1824) , ix + 29 pp. 



39. Eichwald refers, by the way, to the work of the 

 great Professor L. Bojanus (L. Bojanus, "Uber das 

 Verhaltniss der membrana decidua und reflexa zum 

 Ei des menschlichen Embryo," Vilna, 1820). 



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