GENERATION OF ANIMALS, I. xviii. 



" [Seminal fluid is the name given to that which 

 comes from the generating parent, in the case of those 

 animals whose nature it is to copulate, and it is that 

 in which a generative principle is first found. Semen 

 (seed) is the name given to that which contains the 

 principles derived from both the parents which have 

 copulated, as in the case of the plants and certain 

 animals in which male and female are not separate, 

 Uke the first mixture which is formed fi-om the male 

 and female, being as it were a sort of fetation or egg — 

 for these objects too already contain that which comes 

 from both parents. 



Semen (seed) and fruit differ by the " prior and 

 posterior ** " : fruit (is posterior) in that it is derived 

 from something else, whereas seed <is prior) in that 

 something else is derived from it, since in fact they 

 are both one and the same thing. 



We must now resume and state what is the primary 

 nature of semen, as it is called.] 



Now every substance, whatever it may be, that we 

 find in the body, must of necessity be one of the 

 following : (1) one of the parts which are there in 

 accordance with nature, in which case it will be one 

 of the imiform or non-uniform parts ; (2) one which 

 is there contrary to nature, e.g., a tumour ; (3) re- 

 sidue '^ ; (4-) colliquescence ** : (5) nourishment. By 

 residue I mean that which is left over as surplus from 

 the nourishment ; by colUquescence that which is 

 given off as an abscession * from the material that 



*■ The meaning of these terms is discussed in Met, 

 101Sb9ff. 



« See Introd. §§ 65 if. 



■* See Introd. § 67 : also 735 a 27 if. and De somno et 

 Tig. 456 b 34 if. 



' See Introcl. § 67. 



77 



