XXI. WHY DO TAME SOWS FARROW OFTEN, SOME AT, ONE TIME AND OTHERS AT ANOTHER; AND THE WILD BUT ONCE A YEAR, AND ALL OF THEM ABOUT THE SAME TIME AT THE BEGINNING OF SUMMER, WHENCE IT IS SAID,— The wild sow farrowing, that night falls no rain? Is it because of plentiful feeding, as in very truth fulness doth produce wantonness? For abundance of nourishment breeds abundance of seed both in animals and plants. Now wild sows live by their own toil, and that with fear; the tame have always food enough, either by nature or given them. Or may it not be ascribed to their rest and exercise? For the tame do rest and go not far from their keepers; the wild get to the mountains, and run about, by which means they waste the nutriment, and consume it upon the whole body. Therefore either through continual converse, or abundance of seed, or because the females feed in herds with the males, the tame sows call to mind coition and stir up lust, as Empedocles talks of men. But in wild sows, which feed apart, desire is cold and dull for want of love and conversation. Or is it true, what Aristotle says, that Homer called the wild boar χλούνης, because he had but one stone? For most boars spoil their stones (he says) by rubbing them against stumps of trees.