ON GENERATION. 395 



of the foetal chick's existence a more delicate food is prepared 

 for it ; more advanced, firmer and firmer food is supplied ; and 

 this is the reason, I apprehend, wherefore, the perfect egg con- 

 sists not only of two portions of different colours, but is even 

 provided with two kinds of albumen. 



Now all this that we discover from actual experience of the 

 matter accords with the opinion of Aristotle, where he says r 1 

 " The part which is hot is best adapted to give form to the 

 limbs ; that which is more earthy rather conduces to the con- 

 stitution of the body and is more remote. Wherefore in eggs 

 of two colours, the animal begins to be engendered from the 

 white (for the beginning of animal life is in the hot), and derives 

 its nourishment from the yellow. In the warmer animals, con- 

 sequently, these parts are kept distinct from one another, viz. 

 that from which the beginning is derived, and that whence the 

 nourishment is obtained, and the one is white, the other yellow." 



From what has now been said it appears that the chick 

 and we shall show that it is not otherwise in all other animals 

 arises and is constituted as it were by a principle or soul 

 inherent in the egg, and that in the same way the proper ali- 

 ment is sought for and is supplied within the egg ; whereby it 

 comes that the chick is not dependent on its mother in the 

 same way as plants are dependent on the ground ; and it is 

 not more correct to say that the chick is nourished by the 

 blood of its mother, or that its heart beats, and that it lives 

 through the spirits of its parent, than it would be to assert that 

 it moved and felt through the organs, or grew and attained to 

 adult age through the vital principle of its parent. It is mani- 

 fest, on the contrary, and is allowed by all that the foetal chick 

 is nourished through its umbilical vessels; and that the vascular 

 ramifications dispersed over the albumen and yelk imbibe nou- 

 rishment from them and convey it to the foetus. It is also ad- 

 mitted that the chick, when excluded from the shell, is supplied 

 with nourishment, partly from yelk, partly from chyle, and 

 that in either case the aliment passes by the same route, viz. 

 by the vena portse into the liver, the branches of this vessel 

 effecting the transit. 



It is therefore obvious, as I now say by the way, that the 



1 De Gen, Anim. lib. iii, cap. 1. 



