BOOK X. Lxxxiii. 181-LXXXIV. 184 



mares that have been broken are in heat 60 days 

 sooner than those running with the herd ; that swine 

 only foarn at the mouth when mating ; that when a 

 boar-pig has heard a sow in heat grunting it refuses 

 food to the point of losing flesh entirely unless it is ad- 

 mitted to her, while sows get so fierce that they will 

 gore a human being, especially one wearing white 

 clothes. This madness can be reduced by sprinkling 

 the organs with vinegar. It is believed tiiat desire 

 for mating is also stimulated by artieles of diet, for 

 instance rocket in the case of a man and onions in the 

 case of cattle. It is a remarkable fact that wild species 

 when domesticated refuse to breed, for instance wild 

 geese, and wild boars and stags do so reluctantly and 

 only if they have been reared from infancy. Female 

 animals refuse intercourse when pregnant, except 

 the mare and the sow ; but only the common rabbit 

 and the hairy-footed rabbit allow superfetation. 



LXXXIV. All viviparous species produce their Posiure 0/ 

 young head foremost, the embryo turning round aiblnh^" 

 shortly before delivery, but otherwise lying stretched 

 at length in the womb. Four-footed species are 

 carried with the legs stretched out to fuU length and 

 folded against their own belly, but the human embryo 

 curled up in a ball, with the nostrils placed between 

 the two knees." It is thought that moon calves, 

 about which we have spoken before,* are produced 

 when a woman has conceived not frora a male but 

 from herself alone, and that they do not come 

 alive because they are not produced from two parents, 

 and they possess the self-nourishing vitaUty that 

 belongs to plants and trees. Of all the species 

 bearing fully developed otfspring pigs alone have 

 Utters that are numerous as well as developed, for it 



409 



