I
How the Chicken Gets Inside the Egg
There is no more fascinating sight to be seen anywhere than an incubator full of eggs just as the chickens begin to hatch out. You look through the little glass window in the side and see, at first, only rows of clean white eggs, dozens upon dozens of them, looking as if they were all ready to go into the family ice-chest or to be made into omelets for breakfast.
But they are not. First you begin to hear faint scratchy sounds. Pretty soon, here and there, a hole breaks through the broad end of an egg, and a tiny bill sticks out. The little chick is packed so tightly into the egg that it can move only its head. So it pecks and pecks; and stops to rest; and pecks again; and the hole in the shell gets larger and larger; until by and by, the egg cracks open, and a brand-new chicken draws its first long breath and looks out into the world.
After that, the chick usually takes a long rest, for it is pretty tired. When it feels better, it begins to move its legs and wings, and a half-hour or more after it first began work, it gets clear of the shell and stands up on wabbly legs, wet, bedraggled, weary, as disconsolate looking a little object as can well be imagined. Shortly, however, the feathers, which at first were plastered tight to the skin, dry off and fluff out, the legs get steady, and soon there is running about a rolypoly yellow chick, seemingly at least twice as large as the egg which held him only an hour before. Truly it is a wonderful sight, five hundred eggs turning into little chicks in an incubator, for all the world like the kernels of corn changing to pop-corn in the popper.
But wonderful as it is to see the way a chick comes out of an egg, it is still more wonderful to see the way it gets in. A fresh, new-laid egg has no chick inside. After it has been kept warm three weeks, it has—all ready to come out. The question is how the chicken got there.
Many different men have studied this question. For the most part, they have started a dozen or more eggs at once, and then taken them one by one and two or three hours apart, and cautiously broken them open to see what was inside. Sometimes, however, a student of eggs carefully cuts away the shell on one side, until he has made a hole about the size of a ten-cent piece. Over this he cements a sheet of glass as thin as paper, so that he can look through this tiny window into the egg, and see the chick grow.
This is really easier than it sounds. The yolk, as everyone must have noticed in hard-boiled eggs, does not stay in the middle of the egg, but always floats to the upper side. The chick, too, always forms on the upper side of the yolk; and when the egg gets turned over, the yolk rolls round like a barrel in the water and brings the chick to the upper side. So the chick, until it grows big enough to be a tight fit, always lies crosswise of the egg, on the upper side of the yolk just under the shell.
At first, of course, there is no chick at all, but only a round white fleck hardly larger than the head of a large pin, on the side of the yolk where the chick is by and by going to be. Before the end of the first day after the egg is laid, this little fleck has become somewhat oval in outline and an eighth of an inch across. Through its center runs a whiter line, as thick as heavy basting cotton and a sixteenth of an inch long; about half as large, that is, as an “l” or a figure “1” in the type on this page.
This is the beginning of the chick. Only it has hardly yet begun to be a chick, for it has as yet neither head, tail, wings, legs, eyes, nose, mouth, heart, stomach, brain, nor any other parts. It is in short, only a tiny line of chicken substance, which is now to begin to be made into a chicken.