Über entwickelungsgeschiche der Thiere. Beobachtung und Reflexion.
Königsberg: Bei den Gebrüdern Bornträger, 1828. 4to. xxii, 271,  pp. FIRST EDITION. A PRESENTATION COPY. With 3 folding handcoloured engravings. Original wrappers bound into contemporary pasteboards, rebacked. Presentation copy inscribed in French to M. Valenciennes; gift bookplate of the Boston Society of Natural History, by the bequest of its first president, Benjamin D. Greene, M.D., dated 1863. Item #12916
PRESENTATION COPY. FIRST EDITION of the first part of von Baer's classic of embryology, complete in itself. The author here treats the development of the chicken in the egg. He describes vertebrate embryonic development from conception to birth, effectively ending any belief in the preformation theory of embryonic development. According to Singer, von Baer's four important advances in embryology include "the discovery of the mammalian ovum; the proposition known as the germ-layer-theory; the law of corresponding stages in the development of the embryo; and the discovery of the notochord." Presentation copies of von Baer's works are notoriously rare. The second and third parts to this series were published in 1837 and 1888. "Über entwickelungsgeschiche was never finished – the second volume appeared in incomplete form nine years after the first, in response to the demands ofthesubscribers; and the conclusion, also incomplete, was not issued until 1888, twelve years after Baer's death and fifty years after it was written" (Norman).