Chapter XVIII.

1. Generally speaking, the sexual desires of animals are more violent in spring. They do not all, however, copulate at the same seasons, but at the time of year which will cause them to produce their young at the proper season. The period of gestation in domestic swine is four months. They never produce more than twenty pigs; and if they have many, they cannot bring them all up. When aged, they produce in the same manner, but they copulate more slowly. They become pregnant with one act of coition; but they submit themselves to the boar very frequently, on account of their rejection of the capria after they are pregnant. This takes place in all, but some will also eject the semen.

2. If any of the pigs are injured or deteriorated during pregnancy, it is called metachæron. This may take place in any part of the uterus. In parturition the sow gives the first teat to the first pig. It is not necessary that she should go to the boar as soon as the sexual appetite is felt, or before her ears begin to hang down; for otherwise she desires to go again. If she goes to the boar when she is desirous of it, the impregnation is complete in a single act of intercourse. Barley is a proper food for the boar at the period of coition. It should be cooked for the female after parturition. Some sows produce excellent pigs from the first; others do not produce good offspring and pigs till they are grown up. Some persons say that if one of the eyes of a sow is put out, she generally speaking dies very soon. Most of them live fifteen. Some die in less than twenty years.