Wilhelm (William) Th. Preyer: Specielle physiologie des embryo. pp. 644 (Grieben, Leipzig 1885)

Abstract

Preyer was a prolific writer on physiological chemistry and general scientific problems at the end of the last century: his book Die Seele des Kindes established him as one of the founders of modern developmental psychology (Eckardt, Bringmann and Sprung, 1985) and Specielle Physiologie des Embryo (SPE) was the stimulus for Joseph Needham’s Chemical Embryology, written 46 years later (Needham, 1931, 1959; Schroder, 1992). Both Preyer and Needham followed the same systematic and comprehensive approach to the reproductive sciences; their kinship is based on the rigorous application of factual knowledge, of the concepts of natural sciences and of logic and, perhaps, on the same stroke of brilliance and excellency. There is a French translation (Preyer, 1887) of Preyer’s book but none into English which leaves us with translating an old-fashioned German text (in style and orthography) into modern English without losing its charm. The book was written at a time when physical and chemical methods for ‘exploring life’ and ‘organic matter’ were starting to be vigorously applied. For Preyer, ‘ . . . a biochemical and physiological embryognosis . . . is a necessity to understand the fetus’. He intended that SPE (and Die Seele des Kindes) should clarify the origin of functions of life in man by proving their identity with animal functions; further, to demonstrate the applicability of physiological methods to this end, and to establish the importance of studying the development of function to an understanding of physiology, morphology, pathology, education and psychology. To these classic objectives of a natural scientist he added, ‘ . . . it affords great intellectual satisfaction to investigate the successive formation of function beginning with the embryonic state, where it is unintelligible, until it has matured’. And he was excited about the responsibility and the prospects: ‘I know, with the exception of Harvey, no other previous physiologist who has made the exploration of the fetal functions his own business’. The title should be translated as ‘Selective Physiology of the Embryo’, for Preyer refers to the paucity of information which prevented him from writing a complete ‘General Physiology of the Embryo’ as intended originally. The book has nine chapters, nine plates and 552 references, some with long annotations. The first two of the three appendices are devoted to his favourite experimental animals, the chick and the guinea-pig: (i) Physiological observations on the chick in the egg from the first to the last day of incubation and its behaviour shortly after hatching. (ii) Observations of the author on living embryos of the