Aristotle 33 



(see p. 14). His view Aristotle declines to share. * We must ', he 

 says, ' say the opposite of what the ancients said. For whereas 

 they said that semen is that which comes from all the body, we 

 shall say that it is that whose nature is to go to all of it, and what 

 they thought a waste-product seems rather to be a secretion.' 

 According to Aristotle semen is derived from the same nutritive 

 material in the blood-vessels that is distributed to the rest of 

 the body. The semen, however, is strained or secreted off 

 from this nutritive material as being its most essential and 

 representative portion before the distribution actually takes 

 place. 1 But why, it may be asked, if the semen does not come 

 from the various parts of the body, is it yet able to reproduce 

 those various parts ? The answer, on the Aristotelian view, 

 seems to be that the semen contains special and peculiar 

 fractions of the nutritive fluid which have been so modified 

 and adapted that, if not secreted off as semen, they would be 

 distributed to the different parts of the body to nourish each 

 of these various parts. These substances have been elaborated 

 by the soul or vital principle in a manner that is specifically 

 suited for each organ, hand, liver, face, heart, &c., and from 

 each of these specific substances a specific essence is separated 

 oft into the semen corresponding to hand, liver, face, heart, &c.. 

 of the offspring. 



The next question that arises is the mechanism by which the 

 offspring come to resemble their parents. The mechanism in the 

 case of inheritance from the father is comprehensible when we 

 consider the origin and nature of the semen, but the inheritance 

 from the mother requires further explanation. The view of 

 Aristotle is based upon the nature of the catamenia and their 

 disappearance during gestation. ' The catamenia ', in his view, 

 ' are a secretion as the semen is.' 2 The female contributes the 

 material by which the embryo grows and she does this through 



1 De generatione animalium^ i. 18 ; 725* 22. 



2 De generatione animalium^ i. 19; 727* 31. 

 2540-1 C 



