ON GENERATION. 309 



which supplies both matter and form to the being engendered ; 

 so in like manner in the generation of the most perfect animals 

 where principles are distinguished, and the seminal elements 

 of animated beings are divided, a new creation is not effected 

 save by the concurrence of male and female, or by two neces- 

 sary instruments. Our hen's egg is of this kind; to its pro- 

 duction in the perfect state the cock and the hen are necessary. 

 The hen engenders in herself, and therefore does she supply 

 place and matter, nutriment and warmth ; but the cock confers 

 fecundity; for the male, as Aristotle says, 1 always perfects ge- 

 neration, secures the presence of a sensitive vital principle, and 

 from such an egg an animal is engendered. 



To the cock, therefore, as well as to the hen, are given the 

 organs requisite to the function with which he is intrusted ; in 

 the hen all the genital parts are adapted to receive and contain, 

 as in the cock they are calculated to give and immit, or prepare 

 that which transfers fecundity to the female, ne engendering, 

 as it were, in another, not in himself. 



When we anatomize the organs appropriated to generation, 

 therefore, we readily distinguish what each sex contributes in 

 the process ; for a knowledge of the instruments here leads us 

 by a direct path to a knowledge of their functions. 



EXERCISE THE THIRTY-NINTH. 



Of the cock and the particulars most remarkable in his 

 constitution. 



The cock, as stated, is the prime efficient of the perfect or 

 fruitful hen's egg, and the chief cause of generation : without 

 the male no chick would ever be produced from an egg, and 

 in many ovipara not even would any egg be produced. It is, 

 therefore, imperative on us that we look narrowly into his 

 offices and uses, and inquire particularly what he contributes 

 to the egg and chick, both in the act of intercourse and at 

 other times. 



1 Op. cit. 



