(60.) There are three kinds of herons, called, respectively, the leucon,[3106] the asterias,[3107] and the pellos.[3108] These birds experience great pain in coupling; uttering loud cries, the males bleed from the eyes, while the females lay their eggs with no less difficulty.
The eagle sits for thirty days, as do most of the larger birds; the smaller ones, the kite and the hawk for instance, only twenty. The eagle mostly lays but one egg, never more than three. The bird which is known as the “ægolios,”[3109] lays four, and the raven sometimes five; they sit, too, the same number of days as the kite and the hawk. The male crow provides the female with food while she is sitting. The magpie lays nine eggs, the malancoryphus more than twenty, but always an uneven number, and no bird of this kind ever lays more; so much superior in fecundity are the smaller birds. The young ones of the swallow are blind at first, as is the case also with almost all the birds the progeny of which is numerous.
CHAP. 80.—WHAT EGGS ARE CALLED HYPENEMIA, AND WHAT CYNOSURA. HOW EGGS ARE BEST KEPT.
The barren eggs, which we have mentioned as “hypenemia,” are either conceived by the females when they are influenced by libidinous fancies, and couple with one another, or else at the moment when they are rolling themselves in the dust; they are produced not only by the pigeon, but by the common hen as well, the partridge, the pea-hen, the goose, and the chenalopex; these eggs are barren, smaller than the others, of a less agreeable flavour, and more humid. There are some who think that they are generated by the wind, for which reason they give them the name of “zephyria.” The eggs known as “urina,” and which by some are called “cynosura,”[3110] are only laid in the spring, and at a time when the hen has discontinued sitting. Eggs, if soaked in vinegar, are rendered so soft thereby, that they may be twisted[3111] round the finger like a ring. The best method of preserving them is to keep them packed in bean-meal, or chaff, during the winter, and in bran during the summer. It is a general belief, that if kept in salt, they will lose their contents.
CHAP. 81. (61.)—THE ONLY WINGED ANIMAL THAT IS VIVIPAROUS, AND NURTURES ITS YOUNG WITH ITS MILK.
Among the winged animals, the only one that is viviparous is the bat; it is the only one, too, that has wings formed of a membrane. This is, also, the only winged creature that feeds its young with milk from the breast. The mother clasps her two young ones as she flies, and so carries them along with her. This animal, too, is said to have but one joint in the haunch, and to be particularly fond of gnats.
CHAP. 82. (62.)—TERRESTRIAL ANIMALS THAT ARE OVIPAROUS.—VARIOUS KINDS OF SERPENTS.
Again, among the terrestrial animals, there are the serpents that are oviparous; of which, as yet, we have not spoken. These creatures couple by clasping each other, and entwine so closely around one another, that they might be taken for only one animal with two heads. The male viper thrusts[3112] its head into the mouth of the female, which gnaws it in the transports of its passion. This, too, is the only one among the terrestrial animals that lays eggs within its body—of one colour, and soft, like those of fishes. On the third day it hatches its young in the uterus, and then excludes them, one every day, and generally twenty in number; the last ones become so impatient of their confinement, that they force a passage through the sides of their parent, and so kill her. Other serpents, again, lay eggs attached to one another, and then bury them in the earth; the young being hatched in the following year. Crocodiles sit on their eggs in turns, first the male, and then the female. But let us now turn to the generation of the rest of the terrestrial animals.