GENERATION OF ANIMALS, III. i. 



whereas the heavy birds and those fliers which have 

 bulky bodies (such as pigeons and the like) do so. 

 In those birds which are heavy and are not fliers, 

 such as common fowls, partridges, and the like, a 

 great deal of this residue is formed, and that is why 

 their males copulate frequently and their females 

 emit a great deal of matter ; also, some birds of 

 this sort lay many eggs, some lay many times ; thus 

 the common fowl, the partridge and the ostrich 

 lay a large number ; whereas the pigeon family do 

 not lay a large number, but lay many times, the 

 reason being that the last-named stand midway 

 between the crook-taloned birds and the heavy 

 birds ; they are fliers, like the former, and have a 

 bulky body, hke the latter. The result is : (1) As 

 they are fliers, the residue is diverted to their wings ; 

 hence they lay but few eggs ; (2) they are bulky in 

 build, their stomach is hot and very good at con- 

 coction, and, in addition, they can easily get their 

 food, whereas the crook-taloned birds have difficulty 

 in getting it ; hence they lay often. 



Small birds, too, copulate frequently and are very 

 prolific, just as some small plants are : the material 

 which might produce increase of bulk turns into 

 seminal residue. On this account the Adrianic 

 fowls " are extremely prolific ; as they are small in 

 size, the nourishment is used up for the production 

 of offspring. Also, low-bred birds are more proUfic 

 than high-bred ones,*" because their bodies are more 



' Thompson's terras {loc. eii.). The definition of yewalos 

 is given at H.A. 488 b 18 ff. : evyeves y.ev yap eart to e| 

 ayadov yevovs, yewaiov Se to y.T] i^iardfievov eV t-^? avrov 

 <f>vaecos, whence it appears that ycwaio? = " thoroughbred," 

 as Thompson there translates it. 



267 



