GENERATION OF ANIMALS, II. vi. 



get merely the leavings and the residues of it. In 

 every instance, of course, there is nourishment of 

 two grades present : (1) " nutritive," that is to say, 

 which proWdes both the whole and the parts ^nth 

 being ; (2) " growth-promoting," that is to say, which 

 causes increase of bulk. These ^%ill have to be more 

 particularly distinguished later on." The sinews are 

 constructed in the same way as the bones, and out 

 of the same materials, viz., the seminal or " nutri- 

 tive " residue. As for nails, hair, hoofs, horns, bills, 

 cocks' spure and any other such part, these are formed 

 out of the supplementary or " growth-promoting " 

 nourishment, this additional nourishment being 

 obtained from the female, and from outside. On this 

 account, the bones continue growing only up to a 

 certain point, for as all animals have a hmit to then- 

 size, this involves a limit to the growth of the bones. 

 If the bones continued growing for ever, then every 

 animal which contains any bone or the counterpart 

 of bone ^ would go on growing as long as it hved, 

 because the bones set the limit for an animal's size. 

 We shall have to explain later on whv the bones 

 do not continue growing for ever. Hair and similar 

 things, on the other hand, continue growing so long 



it maintains the creature^s being. And it is also " productive 

 of generation " — not, of course, of the generation of the 

 creature which is getting the nourishment, for its " being " 

 is already there, but of another creature similar to it (416 b lo- 

 ll). It thus appears that the business of "nutrition" is 

 concerned \*ith the maintenance of a living creature's being, 

 and with the generation of new ones' being : " growth-pro- 

 motion " is concerned with increasing the bulk of that which 

 already has being — and this is precisely the distinction which 

 Aristotle employs in the present passage. 



* e.g., the os sepiae, the '* pen " of calamaries, the cartilagin- 

 ous spines of Selachia (sharks, etc.) {P. A. 6Si a ^0, 655 a 23). 



233 



