But it is mice that surpass all the other animals in fecundity; and it is not without some hesitation that I speak of them, although I have Aristotle and some of the officers of Alexander the Great for my authority. It is said that these animals generate by licking one another, and not by copulation. They have related cases where a single female has given birth to one hundred and twenty young ones, and in Persia some were found, even pregnant themselves,[1] while yet in the womb of the parent. It is believed also that these animals will become pregnant on tasting salt. Hence we find that we have no longer any reason to wonder how such vast multitudes of field-mice devastate the standing corn; though it is still a mystery, with reference to them, in what way it is that such multitudes die so suddenly; for their dead bodies are never to be found, and there is not a person in existence that has ever dug up a mouse in a field during the winter. Multitudes of these animals visit Troas, and before this they have driven away the inhabitants in consequence of their vast numbers.

They multiply greatly during times of drought; it is said also that when they are about to die, a little worm grows in their head. The mice of Egypt have hard hairs, just like those of the hedge-hog. They walk on their hind feet, as also do those of the Alps. When two animals couple of different kinds, the union is only prolific if the time of gestation is the same in both. Among the oviparous quadrupeds, it is generally believed that the lizard brings forth by the mouth, though Aristotle denies the fact. These animals, too, do not sit upon their eggs, as they forget in what place they have laid them, being utterly destitute of memory; hence it is that the young ones are hatched spontaneously.