278 ON GENERATION. 



must infallibly conclude that the egg, even when contained in 

 the ovary, does not live by the vital principle of the mother, but 

 is, like the youth who comes of age, made independent even 

 from its first appearance; as the acorn taken from the oak, and 

 the seeds of plants in general, are no longer to be considered 

 parts of the tree or herb that has supported them, but things 

 made in their own right, and which already enjoy life in virtue 

 of a proper and inherent vegetative power. 



But if we now admit that there is a living principle in a fertile 

 egg, it may become matter of discussion whether it is the same 

 living principle which already inheres in the egg that will in- 

 here in the future chick, or whether it is a different one that 

 actuates each ? For it is matter of necessity that we admit the 

 inherence of a certain principle which constitutes and causes 

 the egg to grow, and which farther engenders and makes the 

 chick to increase. We have to inquire, therefore, whether the 

 animating principle of the egg and of the chick be one and the 

 same, or several and different ? And then, were several vital 

 principles recognized, some appertaining to the egg, others to 

 the chick, we should next have to inquire : whence and at what 

 epoch the animating principle of the chick entered it? and what 

 is it in the egg which causes the cicatricula to dilate before the 

 advent of the living principle; which draws the eye of the vitellus 

 upwards, as stated, and produces the colliquament, changes the 

 constitution of the fluids of the egg, and preordains everything 

 for the construction of the future chick before there is even a 

 vestige of it to be seen? Or whence shall we say the aliment fit 

 for the embryo is derived, and by which it is nourished and 

 made to grow, before it is yet in being ? For these acts are 

 seen to be the work of the vegetative soul of the embryo, and 

 have reference to the coming pullet, ensuring its nutrition and 

 growth. And again, when the embryo is begun, or the chick 

 is half formed, what is it which constitutes that embryo or that 

 chick one and continuous and connex with the liquids of the 

 egg ? What nourishes and makes the chick to grow, and pre- 

 serves the fluids that are fit for its nutrition from putrefaction, 

 and prepares, and liquefies, and concocts them ? 



If the vital principle be the act of the organic body possessing 

 life inpotentia, it seems incredible that this principle can inhere 

 in the chick before something in the shape of an organized body 



