ON GENERATION. 283 



and veins, and are nourished by the same food as herself. 

 Because, as we have stated in our history, all the vitellary 

 specks do not increase together, like the grapes of a bunch, or 

 the corns of an ear of wheat, as if they were pervaded by one 

 common actuating force or concocting and forming cause; 

 they come on one after another, as if they grew by their own 

 peculiar energy, each that is most in advance severing itself 

 from the rest, changing its colour and consistence, and from 

 a white speck becoming a yelk, in regular and determinate se- 

 quence. And what is more particularly astonishing is that 

 which we witness among pigeons and certain other birds, where 

 two yelks only come to maturity upon the ovarian cluster to- 

 gether, one of which, for the major part, produces a male, the 

 other a female, an abundance of other vitellary specks remaining 

 stationary in the ovary, until the term comes round for two 

 more to increase and make ready for a new birth. It is as if 

 each successive pair received fertility from the repeated addresses 

 of the male ; as if the two became possessed of the vital prin- 

 ciple together; which, once infused, they forthwith increase 

 spontaneously, and govern themselves, living of their own not 

 through their mother's right. And, in sooth, what else can 

 you conceive working, disposing, selecting, and perfecting, as 

 respects this pair of vitellary papulae and none others, but a pe- 

 culiar vital principle ? And although they attract nourishment 

 from the mother, they still do so no otherwise than as plants 

 draw food from the ground, or as the embryo obtains it from 

 the albumen and vitellus. 



Lastly, since the papula existing in the ovary receives fecundity 

 from the access of the male, and this of such a kind that it passes 

 into the form and likeness of the concurring male, whether he 

 were a common cock or a pheasant, and there is as great diversity 

 in the papulae as there are males of different kinds; what shall we 

 hold as inherent in the papulae themselves, by whose virtue they 

 are distinguished from one another and from the mother? 

 Undoubtedly it must be the vital principle by which they are 

 distinguished both from each other and from the mother. 



It is in a similar manner that fungi and parasitic plants live 

 upon trees. And besides, we in our own bodies frequently suffer 

 from cancers, sarcoses, melicerides, and other tumours of the 



