The embryology of insects is entirely a study of the last century.
Kowalevsky or a bug is invaginated into the yolk at the head end, the portion of (1871 and 1887) on the embryology of the water-beetle Hydrophilus the blastoderm necessarily pushed in with it forming the amnion.
xx., 1880; Kingsley, " The Embryology of Limulus," Journ.
Von Baer, however, has another place in the history of zoology, being the first and most striking figure in the introduction of embryology into the consideration of the relations of animals to one another.
and xxv.; "Contributions to the Embryology of the Marsupialia," Quart.