138 EMBRYOLOGY IN THE SEVENTEENTH [pt. 11 



others. To have occupied himself with the chemical properties of 

 those substances which afford the raw material of development was 

 a great step for those times, but it was not until some twenty-five 

 years later that Walter Needham carried this new interest into the 

 mammalian domain, and made chemical experiments there. 



3-4. William Harvey 



The Latin edition of William Harvey's book on the generation of 

 animals appeared in 1651, and the English in 1653. The frontispiece 

 of the former which is reproduced as the frontispiece of this book is 

 a very noteworthy picture, and derives a special interest from the 

 fact that on the egg which Zeus holds in his hands is written, "^x 

 ovo omnia'\ — a conception which Harvey is continually expounding 

 (see especially the chapter, "That an egg is the common Original 

 of all animals"), but which he never puts into epigrammatic form 

 in his text, so that the saying, omne vivum ex ovo, often attributed 

 to him, is only obliquely his. 



The De Generatione Animalium was written at different times during 

 his life, and not collected together for publication until George Ent, 

 of the College of Physicians, persuaded Harvey to give it forth about 

 1650. As early as 1625 Harvey was studying the phenomena of 

 embryology, as is shown among other evidences by a passage in his 

 book where he says, "Our late Sovereign King Charles, so soon as 

 he was become a man, was wont for Recreation and Health sake, 

 to hunt almost every week, especially the Buck and Doe, no Prince 

 in Europe having greater store, whether wandring at liberty in the 

 Woods and Forrests or inclosed and kept up in Parkes and Chaces. 

 In the three summer moneths the Buck and the Stagge being then 

 fat and in season were his game, and the Doe and Hind in the 

 Autumme and Winter so long as the three seasonable moneths con- 

 tinued. Hereupon I had a daily opportunity of dissecting them and 

 of making inspection and observation of all their parts, which liberty 

 I chiefly made use of in order to the genital parts". Nor was Harvey 

 less diligent in examining the generation of ovipara. John Aubrey, 

 in his Brief Lives, says, " I first sawe Doctor Harvey at Oxford in 1642 

 after Edgehill fight, but I was then too young to be acquainted with 

 so great a Doctor. I remember that he came often to Trin. Coll. 

 to one George Bathurst, B.D. who kept a hen in his chamber to 



