196 GENERATION AND DEVELOPMENT. 



(3) From butterflies and some other animals, sJcolekes 

 or larvae are produced, and these are not like the parents. 



(4) Animals which are not deformed may be generated 

 by deformed parents. 



For reasons such as these he concluded that the sperm 

 was not derived from all parts of the parents. He says that 

 it is more fitting that it should be produced from homoeo- 

 meria, these being anterior to and forming the anhomcBomeria.* 

 Proceeding then to a more definite conclusion, he says that 

 the sperm is a part of the superfluous matter of the blood, 

 or something analogous to it.t He does not, however, 

 clearly express his views about the nature of this superfluous 

 matter and its mode of separation, but his meaning, ex- 

 pressed chiefly in G. A. i. c. 19, 7266, seems to be that, after 

 some parts of the blood have been disposed of as nutritive 

 or formative material for the flesh and other parts of the 

 body, there remain a part which is the last to be supplied to 

 the parts of the body and a residual or superfluous part, 

 which is of a very useful nature and has great power (Jwa/zi?). 

 This constitutes the sperm, and since it is like the part, 

 referred to above, which is the last to be supplied to the 

 parts of the body, it is reasonable that it should be capable 

 of forming parts similar to these, i.e., similar to the parts of 

 the parents. The sperm, in fact, has potentially in itself 

 each of the parts of the body. It will be noticed that this 

 view bears some resemblance to the evolution theory elab- 

 orated by Bonnet and others, but differs therefrom in the 

 way in which the parts were supposed to exist in the sperm, 

 for, according to the evolution theory, the parts actually 

 existed in miniature in the sperm. 



Aristotle also discusses, at great length, the nature of 

 the material, if any, contributed by the male and the female. 

 He concludes that the female contributes the material of 

 the embryo, and that such material is derived from the 

 catamenia. He seems to have believed that the material 

 contributed by the female was passive formative material.! 

 The essential generative agency, he believed, was contributed 

 by the male, but it was not necessary for anything material to 

 pass from the male to the embryo, for the male contributed 

 not matter but form and motive principle. § So fully did he 

 believe this that he seems to have had no misgiving about 



* G. A. i. c. 18, 722a. f Ibid. i. c. 18, 125a and 726a. 



I Ibid. i. c. 20, 729a. § Ibid. i. c. 20, 729a, i. c. 21, 7296. 



