ii8 FROM GALEN TO THE RENAISSANCE [pt. ii 



development of the chick as Fabricius did, showing the blood- 

 vessels radiating from the minute heart, should have been able 

 to propound the thesis that the chalazae were the material of the 

 embryo. 



The other biologist to whom Harvey was most indebted was 

 Andreas Laurentius of Montpellier, whose Historia Anatomica (printed 

 with his other works in 1628) contained a whole book (viii) devoted 

 to embryology, but which presents us with nothing except a com- 

 mentary on Hippocrates and Aristotle. The only evidences of life 

 are furnished by two polemics, one of which was against Simon 

 Petreus of Paris, who had propounded some new views about the 

 foetal circulation. Laurentius gave also a table showing the changes 

 which occur in the heart and lungs of the foetus at birth. 



It was about this time that the embryological observations of that 

 many-sided genius, Hieronymus Cardanus, began to attract atten- 

 tion. His main thesis was that the limbs of the embryo were alone 

 derived from the yolk, while the rest of the body came from the 

 white. This was a well-meant attempt to mediate between the two 

 traditions headed respectively by Aristotle and Hippocrates, but the 

 arguments in support of it were not even remarkable for ingenuity. 

 Constantinus Varolius treated of the formation of the embryo in a 

 book which appeared in 1591, but very inadequately. He had 

 certainly opened hen's eggs, and describes the fourth-day embryo 

 as forma minimi faseoli. But nearly every one of his marginal 

 headings begins with the word Cur, and this tells its own story, 

 for the didactic style rarely hides genuine works of research. Johannes 

 Fernelius, a rather earlier worker, in his De Hominis Procreatione fol- 

 lowed Aristotle and Galen in nearly all particulars, and made no 

 real contribution to embryology. On its practical obstetrical side, 

 the sixteenth century produced some remarkable compilations of 

 ancient gynaecological writings. The first of these was that of Caspar 

 Wolf, which was published at Ziirich in 1566, and, after having 

 been enlarged by Caspar Bauhin in 1586, subsequently formed the 

 backbone of the most important and famous one, namely, that of 

 Israel Spach (Strassburg, 1597). Although these composite text- 

 books represented no real embryological progress, they yet showed 

 that great interest in development was alive, an interest which, 

 though doubtless utilitarian in its origin, could hardly fail to lead 

 to advances of a theoretical nature. (See Fig. 5.) 



