“The yolk or yelk (which means the yellow part) is round and bright yellow; hence its name. At a point on its surface, generally at the top, no matter what the position of the egg, is seen a circular spot, dull white, where the matter is a little more condensed than elsewhere. It is called the cicatricle, or little scar. That is the sacred spot where lies the spark of life which, animated by incubation, will quicken the substance of the egg and mold it into a living being; it is the point of departure, the origin, the germ of the bird. The yolk itself is the nutritive reservoir whence are drawn the materials for this work of creation. Quickened by the heat of the brooding hen and by the action of the air, it becomes covered with a network of fine veins. These swell with the substance of the yolk, which turns to blood; and this blood, carried hither and thither, becomes the flesh of the being in process of formation. The yolk, then, is the bird’s first food, but food that no beak seizes and no stomach digests, none being in existence yet. It changes to blood and afterward to flesh without the preparatory work of ordinary digestion; it enters the veins directly, and thus nourishes the whole body.
“Animals with udders—the mammifers—also have nutriment for the very young in the form of milk, which is indispensable for the weak stomach of the nursling. Well, the yolk is to the bird in its shell what milk is to the lamb and kitten; it is its milk-food, [[43]]as it can have no recourse to maternal udders. The popular saying has perfectly caught the strict resemblance: they call a drink prepared with the yolk of an egg, ‘hen’s milk.’ ”
“That is what Mother Ambroisine makes me take when I cough in the winter,” said Emile.
“The delicious beverage that Mother Ambroisine gives you when you have a cold is very properly called ‘hen’s milk,’ since it is made with the equivalent of milk; that is to say, the yolk of an egg.” [[44]]
CHAPTER VI
INCUBATION
“Incubation means lying upon. The brooding bird does in fact crouch or lie upon her eggs, warming them with the heat of her body for a number of days with indefatigable patience. When a hen wishes to set,[1] she makes it known by her repeated cluckings, little cries of maternal anxiety, by her ruffled feathers, her restless movements, and particularly by the perseverance with which she stays on the nest, even when it has no eggs, where she has been in the habit of laying.
“Some hens with wandering dispositions go back to the instincts of their wild race. They leave the hen-house and seek a hedge or thicket, where they select a hiding-place to suit them, and there make a little hollow in the earth which they line as well as they can with a mattress of dry grass, leaves, and feathers. That is a nest in the rough, without art, a shapeless construction in comparison with the clever masterpiece of the chaffinch and goldfinch. It is, furthermore, worthy of remark that all the domestic birds, as if man’s intervention had destroyed their skill by freeing them from want, fail to display in [[45]]the construction of their nests the admirable resourcefulness shown by most wild birds. Here might be repeated the saying, as true for man as for beast, necessity is the mother of invention. Sure of finding, when the time comes for laying, the basket stuffed with hay by the hand of the housewife, the domestic fowl does not trouble herself to build a nest, an undertaking in which the tiniest bird of the fields shows itself a consummate architect. At the most, when her adventurous disposition makes her prefer the perilous shelter of the hedge to the safe retreat of the poultry-yard, the hen, gleaning with her beak a few straws and leaves, and plucking, if need be, some of her own feathers, succeeds in making, for her period of brooding, a disordered heap rather than a nest. There, every day, unknown to all, she goes and lays her egg. Then for three whole weeks she is not to be seen, or only at intervals. That is the time of incubation. At last, some fine day, she reappears, very proud, at the head of a family of young chickens, peeping and pecking around her.”
“I should like,” said Emile, “to have some hens that set like that in the fields and then come home again some day with their family of little chickens.”