Problems, Concepts and Their History 



the Renaissance as a movement for freedom 

 with respect to authority, often neglects to 

 remember that it was in part from "author- 

 ity" that the inspiration to achieve freedom 

 derived. 



It was Fabricius, student of Fallopius, 

 himself a student of Vesalius, who first ex- 

 haustively applied the rigorous "new" Ve- 

 salian method of direct observation to the 

 study of embryos, though he had many 

 predecessors who had made isolated obser- 

 vations on embryonic material (among them 

 Columbus, Fallopius, Eustachius, Arantius, 

 Aldrovandus, Goiter et al. Cf. Needham, '34, 

 and Adelmann, ed., in Fabricius, 1942 edi- 

 tion, for full discussion; see also Adelmann 

 for full critical treatment of Fabricius him- 

 self). 



On the observational side, he was the first 

 to publish illustrations based on systematic 

 study of the development of the chick, and 

 this, though he neglected to describe them 

 in detail, was probably his most significant 

 contribution. He made the way easier for 

 the later preformationists by drawing the 

 supposed three and four day chicks much too 

 advanced for their normal chronological age; 

 among his other fallacies, the most notable 

 was his ascription to the chalazae of the role 

 of forming the embryo. Among his improve- 

 ments to the existing embryological knowl- 

 edge was his emphasis that the carina 

 (whose metaphysics he discussed more com- 

 pletely than its embryological fate) is 

 formed before the heart, controverting Aris- 

 totle, and before the liver, taking issue with 

 Galen in both fact and philosophy. He stud- 

 ied the fetal anatomy of various vertebrates, 

 that of many mammals, including man, and 

 presented illustrations of the comparative 

 anatomy of the placenta, showing his spe- 

 cial interest in the umbilical and the fetal 

 circulation, though he devoted himself to 

 Galenic principles in his interpretations of 

 these. Even Fabricius, then, as late as the 

 sixteenth century was exemplifying the con- 

 flict of the Renaissance between allegiance 

 to authority and confidence in direct per- 

 sonal observations. But though in one sense 

 his position represents an inevitable retreat, 

 even behind the position of Aristotle, in that 

 he emphasized the anatomy of embryos 

 rather than the process of development, yet 

 his work looked forward to the new embry- 

 ology in the influence it exerted on William 

 Harvey. 



Fabricius' name, as Adelmann points out 

 {op. cit., p. 115) begins the first sentence 

 of Harvey's text on generation; and Harvey, 



too, like his preceptor, looked back to Aris- 

 totle in his interpretations, for all that his 

 demonstration of the circulation in method, 

 fact, and conception, was to lead to the 

 whole experimental and analytical biology 

 of the future. Harvey followed Bacon's prin- 

 ciple of explaining nature by observation 

 and experiment, and Galileo's of measuring 

 what is measurable and making measurable 

 what is not. Harvey's contemporaries be- 

 lieved, with Fracastorius, that "the motion 

 of the heart was to be understood by God 

 alone" (Harvey, De motu, 1931 edition, p. 

 25). Harvey proved it to be a mechanical 

 function. Yet he could speak of the motion 

 of the blood, after Copernicus, Kepler and 

 Galileo, as "circular in the way that Aris- 

 totle says air and rain follow the circular 

 motion of the stars" {ibid., p. 70) and, like 

 a good Aristotelian, he left the vital spirits 

 remaining in the blood. "Whether or not the 

 heart," he wrote, "besides transferring, dis- 

 tributing and giving motion to the blood, 

 adds anything else to it, as heat, spirits, or 

 perfection, may be discussed later and de- 

 termined on other grounds" {ibid., p. 49). 

 Harvey may have surmised how to treat the 

 organ as a machine, but he was in some 

 ways too Aristotelian to appreciate the im- 

 plications of his own advanced experiment. 



He was not so bound by authority, how- 

 ever, as to be unable to free himself from 

 some of the old embryological errors. He 

 refuted on an observational basis, for in- 

 stance, the notion that right and left repre- 

 sent maleness and femaleness, and he cor- 

 rected the idea of Fabricius concerning the 

 role of the chalazae by demonstrating the 

 cicatricula (our blastoderm) as the source 

 of the embryo; he corrected, too, various 

 specific observational errors of Aristotle. 

 Most important, he abolished for all time 

 the Aristotelian conception of female as sub- 

 stance and male as form. Galen to be sure 

 had seemed to localize both material and 

 efficient causes in both male and female 

 semen, as had Fabricius after him in a con- 

 fused sort of way; but it was Harvey, for all 

 his fanciful speculation concerning the sig- 

 nificance of fertilization, who finally ele- 

 vated the egg to its full and ultimate dig- 

 nity. The processes of development can 

 obviously hardly be investigated before the 

 object that is developing is at least defined 

 as their residence, and Harvey's contribu- 

 tion here was therefore a significant one. 



It is abundantly clear, however, that by 

 egg Harvey meant something different than 

 we do. He knew there was necessary for de- 



