Aristotle's biology 



To return for a moment to some Aristo- 

 telian 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 irdieritance 

 of SD many diverse individual resemblances.*'' 

 He was aware that bodily imperfections in- 

 cidentally acquired would not be inherited, like 

 congenital traits. Yet he realized the con- 

 stitutional 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 phenome- 

 non noticeable with gelded animals.^" Hip- 

 pocrates 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." " 

 He has much to say of migration and hiber- 

 nation. 



In ancient natural science the manner of 



[73] 



