Burdach’s great textbook of physiology was planned to run to 10 vols., but the death of his wife quenched his enthusiasm for the task. Parts of the text were written by von Baer, Rathke, Johannes Müller, R. Wagner and others, under the direction of Burdach. Von Baer’s contribution includes material also published the same year in Ueber Entwicklungsgeschichte der Thiere. Burdach’s unsatisfactory editing of it for Die Physiologie stimulated von Baer to have his own separate book published. See No. 479.

Announces Baer’s discovery of the mammalian ovum, the culmination of a search begun by scientists at least as early as the work of de Graaf in the 17th century (No. 1209). The pamphlet was reprinted in facsimile in Isis, 1931, 16, 315-30. English translation by C. D. O’Malley, Isis, 1956, 47, 117-53.

Baer, the founder of modern embryology, definitely established the “germ-layer theory”, discovered the notochord and the human ovum, and postulated the law of corresponding stages in embryonic development. With Cuvier he is the founder of modern morphology. Later in his life he devoted much time to the study of anthropology. Part of vol. 1 was published in No. 599. In response to demands by subscribers to the treatise, the publishers issued vol. 2 in incomplete form in 1837. The conclusion to vol. 2, sometimes called volume 3, was edited by Ludwig Stieda and published 12 years after von Baer’s death.