Page:Greek Biology and Medicine.djvu/95

 To return for a moment to some Aristotelian opinions bearing on the generation of life and its transmission of attributes to off-spring. He combated pangenesis, the theory that the semen must come from the whole body, in order to account for the inheritance of so many diverse individual resemblances.$49$ He was aware that bodily imperfections incidentally acquired would not be inherited, like congenital traits. Yet he realized the constitutional effects arising from the alteration of a small part or organ: that if animals "be subjected to a modification in minute organs, they are liable to immense modifications in their general configuration,"—a phenomenon noticeable with gelded animals.$50$ Hippocrates had shown how often trouble with one organ worked a general disturbance of the system. Aristotle recognized also that the habits of animals are connected with their main functions of "breeding and the rearing of young, or with procuring a due supply of food; and these habits are modified so as to suit cold and heat and the variations of the season."$51$He has much to say of migration and hibernation.

In ancient natural science the manner of