GENERATION OF ANIMALS, III. vii.-vm. 



living things, as has been said repeatedly ; hence the 

 egg itself, regarded as the fetation of a plant, is 

 perfect, but regarded as the fetation of an animal it 

 is imperfect. If there were no such thing as a male 

 in the class of birds, the egg would have been formed 

 as it is in fishes, supposing there really is some species 

 which generates without a male ; though I mentioned 

 earlier ° in this connexion that this has not yet been 

 sufficiently observed. Actually, however, both sexes 

 exist in all species of birds ; so that, qua plant, the 

 >\ind-egg has reached perfection (and that is why it 

 does not change any more after impregnation),^ qua 

 non-plant, on the other hand, it has not reached per- 

 fection, and nothing else results from it, since it has 

 been formed neither as a plant simply and directly '^ 

 nor as an animal by means of copulation. As for 

 eggs which are the result of copulation, however, but 

 which have been distinguished into white and yolk, 

 these are formed according to the male which impreg- 

 nated them first, since by that time they possess both 

 the required principles.** 



The production of their young is accomplished in VIII 

 the same manner by the Cephalopods — sepias and l^- ^lood- 



i_ 1-1 11 i" /-I f • 1 1 lessanimals. 



the hke— and by the Crustacea — caraboi * and the (i.) Repro- 

 creatures akin to them. They too lay eggs as a cephaio-"' 

 result of copulation ; many instances have been pods and 

 observed of the male uniting with the female. So ™' **'^' 

 here we have another score on which we can con\ict 

 of a lack of scientific accuracy those who allege that 

 all fish are female and produce eggs without copula- 



* At P. A. 683 b 25 Aristotle makes four main groups of 

 of Crustacea : (1 ) caraboi, {2) astacoi, (3) carides, (4) carcinoi, 

 corresponding roughly to ( 1 ) lobsters, (2) crayfish, (3) prawns 

 and shrimps, (4) crabs. 



323 



