102 THE HISTORY OF ANIMALS. [B. V. 



4. All these among birds are barren, (for nature is 

 able to complete them as far as the formation of an egg,) 

 unless persons suppose that there is another method of 

 communicating the male influence, concerning which we 

 shall speak more plainly hereafter. In some fish, after the 

 spontaneous production of the ovum, it happens that living 

 creatures are produced, some by themselves, others by the 

 aid of the male. The manner in which this is done will be 

 made plain in a future place, for nearly the same things take 

 place in the class of birds. 



5. Whatever are produced spontaneously in living crea 

 tures, in the earth, or in plants, or in any part of them, 

 have a distinction in the sexes, and by the union of the 

 sexes something is produced, not the same in any respect, 

 but an imperfect animal, as nits are produced from lice, 

 and from flies and butterflies are produced egg - like 

 worms, from which neither similar creatures are produced, 

 nor any other creature, but such things only. First of 

 all, then, we will treat of coition, and of the animals that 

 copulate, and then of others, and successively of that which 

 is peculiar to each, and that which is common to them all. 



CHAPTER II. 



1. THOSE animals in which there is a distinction of the 

 sexes use sexual intercourse, but the mode of this intercourse 

 is not the same in all, for all the males of sanguineous 

 animals with feet have an appropriate organ, but they do 

 not all approach the female in the same manner, but those 

 which are retromingent, as the lion, the hare, and the lynx, 

 unite backwards, and the female hare often mounts upon 

 the male ; in almost all the rest the mode is the same, for 

 most animals perform the act of intercourse in the same way, 

 the male mounting upon the female ; and birds perform 

 it in this way only. 



2. There are, however, some variations even among birds ; 

 for the male sometimes unites with the female as she sits 

 upon the ground, as the bustard and domestic fowl : in 

 others, the female does not sit upon the ground, as the 

 crane ; for in these birds the male unites with the female 

 standing up ; and the act is performed very quickly, as in 

 sparrows. Bears lie down during the act of intercourse, 



