42 PRELIMINARY NOTE [pt. 



No exhaustive treatise on the history of embryology at present 

 exists. The nearest approach to it is the very valuable memoir of 

 Bruno Bloch with its epitome but this only covers the era of the 

 Renaissance with thoroughness. Hertwig's account, which he printed 

 at the beginning of his great Handbuch der Entwicklungslehre, does not 

 deal very fully with any aspect of the subject before 1800, nor do 

 the much shorter ones of Henneguy and Minot. The latter paper is 

 interesting in that it ends with an emphasis on the need for a physico- 

 chemical attitude in the future. The introduction to Keibel's book 

 is much slighter, but contains some useful information. There are 

 various monographs and papers on special points, such as Pouchet's 

 rather untrustworthy treatment of the embryology of Aristotle, and 

 Lones' discussion of it, which is worse. Camus' notes are still the best 

 commentary on the Historia Animalium. Again, useful information on 

 some cultural points is to be had from the treatise of Ploss & Bartels. 

 The introductions to certain books also contain valuable information, 

 and in this class comes Dareste's remarkable book on teratology. 

 The bibliographies contained in v. Haller's eighth volume and in 

 Heffter's book, are, naturally, of the greatest assistance. 



These reservations made, the principal reviews of the subject are 

 chiefly to be found in histories of science in general, such as Sarton's; 

 histories of biological theory, such as Radl's; histories of obstetrics, 

 such as V. Siebold's, Spencer's and Fasbender's; histories of gynaeco- 

 logy, such as McKay's; and histories of anatomy, such as Singer's 

 and V. Toply's. Histories of medicine as a whole are numerous 

 and helpful: I have found those of Garrison and Neuburger- 

 Pagel most useful. Those which deal with special periods are also 

 of assistance, such as Schrutz and Browne on Arabian, Bloch on 

 Byzantine, and Harnack on Patristic medicine. Histories of chemistry 

 provide no help, for ancient chemistry was so oriented towards 

 "practical" results, such as the lapis philosophorum and elixir vitae, 

 that the egg was only considered as a raw material for various 

 preparations. The investigation of its change of properties during 

 the development of the embryo did not occur to the alchemists. 

 Detailed studies of particular subjects, such as those contained in 

 Singer's two excellent volumes The History and Method of Science, 

 may also be of some assistance. Again, there are books which give 

 a wonderful orientation and an articulate survey of vast tracts : of 

 these Clifford Allbutt's Greek Medicine in Rome, with its mass of 

 references, is among the most valuable. And Miall's Early Naturalists 



