a similar story is told also of the generation of birds. for there are some who say that the raven and the ibis unite at the mouth, and among quadrupeds that the weasel brings forth its young by the mouth; so say anaxagoras and some of the other physicists, speaking too superficially and without consideration. concerning the birds, they are deceived by a false reasoning, because the copulation of ravens is seldom seen, but they are often seen uniting with one another with their beaks, as do all the birds of the raven family; this is plain with domesticated jackdaws. birds of the pigeon kind do the same, but, because they also plainly copulate, therefore they have not had the same legend told of them. but the raven family is not amorous, for they are birds that produce few young, though this bird also has been seen copulating before now. it is a strange thing, however, that these theorists do not ask themselves how the semen enters the uterus through the intestine, which always concocts whatever comes into it, as the nutriment; and these birds have a uterus like others, and eggs are found them near the hypozoma. and the weasel has a uterus in like manner to the other quadrupeds; by what passage is the embryo to get from it to the mouth? but this opinion has arisen because the young of the weasel are very small like those of the other fissipeds, of which we shall speak later, and because they often carry the young about in their mouths.
much deceived also are those who make a foolish statement about the trochus and the hyena. many say that the hyena, and herodorus the heracleot says that the trochus, has two pudenda, those of the male and of the female, and that the trochus impregnates itself but the hyena mounts and is mounted in alternate years. this is untrue, for the hyena has been seen to have only one pudendum, there being no lack of opportunity for observation in some districts, but hyenas have under the tail a line like the pudendum of the female. both male and female have such a mark, but the males are taken more frequently; this casual observation has given rise to this opinion. but enough has been said of this.
