ON GENERATION. 413 



to the parts ; the augmentative, that which causes increase to 

 the bulk." 



This is in accordance with what we find in the egg, where 

 the albumen supplies a kind of purer aliment adapted to the nu- 

 trition of the embryo in its earlier stages, and the yelk affords 

 the material for the growth of the chick and pullet. The 

 thinner albumen, moreover, as we have seen, is used in fashion- 

 ing the first and more noble parts ; the thicker albumen and 

 the yelk, again, are employed in nourishing and making these 

 to grow, and further in forming the less important parts of the 

 body. For," he says, "the sinews, too, are produced in the 

 same way as the bones, and from the same material, viz. : the 

 seminal and nutritive excrementitious matter. But the nails, 

 hair, horns, beak, and spurs of birds, and all other things of the 

 same description, are engendered of the adventitious and nutri- 

 tive aliment, which is obtained both from the mother and from 

 without." And then he gives a reason why man, whilst other 

 animals are endowed by nature with defensive and offensive 

 arms, is born naked and defenceless, which is this : that whilst 

 in the lower animals these parts are formed of remainders or 

 excrements, man is compounded of a purer material, " which 

 contains too small a quantity of inconcoct and earthy matter/' 



Thus far have we followed Aristotle on the subject of ' The 

 Order in Generation/ the whole of which seems to be referrible to 

 one principle, viz. : the perfection of nature, which in her works 

 does nothing in vain and has no short- comings, but still does that 

 in the best manner which was best to be done. Hence in gene- 

 ration no part would either precede or follow, did she prefer 

 producing them altogether, viz. : in circumstances where she 

 acts freely and by election ; for sometimes she works under 

 compulsion, as it were, and beside her purpose, as when through 

 deficiency or superabundance of material, or through some de- 

 fect in her instruments, or is hindered of her ends by external 

 injuries. And thus it occasionally happens that the final parts 

 are formed before the instrumental parts, -understanding by 

 final parts, those that use others as instruments. 



And as some of the parts are genital, nature making use of 

 them in the generation of other parts, as the means of remov- 

 ing obstacles the presence of which would interfere with the 

 due progress of the work of reproduction, and others exist for 



