Pigeons have the peculiarity of billing before they couple; they generally lay two eggs, Nature so willing it, that among birds the produce should be more frequent with some, and more numerous with others. The ring-dove and turtle-dove mostly lay three eggs, and never more than twice, in the spring; such being the case when the first brood has been lost. Although they may happen to lay three eggs, they never hatch more than two; the third egg, which is barren, is generally known by the name of "urinum."[1] The female ring-dove sits on the eggs from mid-day till morning, the male the rest of the time. Pigeons always produce a male and a female; the male first, the female the day after. Both the male and the female pigeon sit on the eggs; the male in the day-time, the female during the night. They hatch on the twentieth day of incubation, and lay the fifth day after coupling. Sometimes, indeed, in summer, these birds will rear three couples in two months; for then they hatch on the eighteenth day of incubation, and immediately conceive again; hence it is that eggs are often found among the young ones, some of which last are just taking wing, while others are only bursting the shell. The young ones, themselves, begin to produce at the age of five months. The females, if there should happen to be no male among them, will even tread each other, and lay barren eggs, from which nothing is produced. By the Greeks, these eggs are called "hypenemia.[2]

(59.) The pea-hen produces at three years old. In the first year she will lay one or two eggs, in the next four or five, and in the remaining years twelve, but never beyond that number. She lays for two or three days at intervals, and will produce three broods in the year, if care is taken to put the eggs under a common hen. The males are apt to break the eggs in getting at the females while sitting, and hence it is that the pea-hen lays by night, and in secret places, or else sits on her eggs in an elevated spot; the eggs will break, too, unless they are received upon some surface that is soft. One male is sufficient for every five females; when there are only one or two females to a male, all chance of their being prolific is spoilt through their extreme salaciousness. The young breaks the shell in twenty-seven days, or, at the very latest, on the thirtieth.

Geese pair in the water, and lay in spring; or, if they have paired in the winter, they lay about forty eggs, after the summer solstice. The hatching takes place twice in the year, if a hen hatches the first brood; otherwise, their greatest number of eggs will be sixteen, their lowest seven. If their eggs are taken away from them, they will keep on laying until they burst; they will not hatch the eggs of any other birds. The best number of eggs for placing under the goose for hatching, is nine, or else eleven. The females only sit, and that for thirty days; but if they are kept very warm, then only twenty-five. The contact of the nettle is fatal to their young, and their own greediness is no less so-sometimes, through overeating, and sometimes through over-exertion; for seizing the root of a plant with the bill, they will make repeated efforts to tear it out of the ground, and so, at last, dislocate the neck. A remedy against the noxious effects of the nettle, is to place the root of that plant under the straw of their nest.

(60.) There are three kinds of herons, called, respectively, the leucon,[3] the asterias,[4] and the pellos.[5] 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,"[6] 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.