452 ON GENERATION. 



formed in the egg? by what agent is either white or yelk 

 turned into blood whilst the liver is not yet in existence ? For 

 in the egg, at all events, he could not say that the blood was 

 transfused from the mother. He says, indeed, " This blood 

 is produced and concocted in the veins rather than in the 

 liver ; but it becomes bone, cartilage, flesh, &c. in the parts 

 themselves, where it undergoes exact concoction and assimila- 

 tion." In this he adds nothing; he neither tells us how or 

 by what means perfect blood is concocted and elaborated in 

 the minute veins both of the albumen and vitellus, the 

 liver, as I have said, not having yet come into existence, 

 not a particle of any part of the body, in fact, having yet been 

 produced by which either concoction or elaboration might be 

 effected. And then, forgetful of what he has previously said, 

 viz. that the hot and hsematous parts are nourished by the 

 vitellus and the cold and anaemic parts by the albumen, he is 

 plainly in contradiction with himself when he admits that the 

 same blood is turned into bone, cartilage, flesh, and all other 

 parts. 



More than this, Fabricius has slipped the greatest difficulty 

 of all, the source of not a little doubt and debate to the 

 medical mind, viz. how the liver should be the source and 

 artificer of the blood, seeing that this fluid not only exists in 

 the egg before any viscus is formed, but that all medical 

 writers teach that the parenchymata of the viscera are but 

 effusions of blood? Is the work the author of its workman? 

 If the parenchyma of the liver come from the blood, how can 

 it be the cause of the blood ? 



What follows is of the same likelihood : " There is another 

 reason wherefore the albumen should be separated from the 

 yelk, namely, that the foetus may swim in it, and be thus 

 supported, lest tending downwards by its own weight, it 

 should incline to one particular part, and dragging, should 

 break the vessels, in preventing which the viscidity and purity 

 of the albumen contribute effectually. For did the foetus grow 

 amid the yelk, it might readily sink to the bottom, and so 

 cause laceration of that body." Sufficiently jejune ! For what, 

 I entreat, can the purity of the albumen contribute to the 

 support of the embryo ? Or how should the thinner albumen 

 sustain it better than the thicker and more earthy yelk? Or 



