ARISTOTLE. 39 



generation; the feminine principle is the origin of the 

 material generated. Aristotle's philosophy of nature was 

 teleological, and the imperfect character of his anatomical 

 knowledge often gives him occasion to explain particular 

 phenomena by final causes. Thus animals producing 

 soft-shelled eggs (e.g. cartilaginous fish and vipers) are 

 said to do so because they have so little warmth that 

 the external surface of the egg cannot be dried. 



Among insects, some (e.g. grasshopper, cricket, ant, 

 etc.) produce young in the ordinary way, by the union of 

 the sexes ; in other cases (e.g. flies and fleas) this union 

 of the sexes results in the production of a skolex ; while 

 others have no parents, nor do they have congress such 

 are the ephemera, tipula, and the like. Aristotle dis- 

 cusses and rejects the theory that the male reproductive 

 element is derived from every part of the body. He 

 concludes that "instead of saying that it comes from all 

 parts of the body, we should say that it goes to them. It 

 is not the nutrient fluid, but that which is left over, which 

 is secreted. Hence the larger animals have fewer young 

 than the smaller, for by them the consumption of nutrient 

 material will be larger and the secretion less. Another 

 point to be noticed is, that the nutrient fluid is universally 

 distributed through the body, but each secretion has its 

 separate organ. ... It is thus intelligible why children 

 resemble their parents, since that which makes all the 

 parts of the body, resembles that which is left over as 



