lightened. But even boiling water does not render the shell more fragile; and though the water should soften it, upon drying in the air it would become as hard as at first*." It is well remarked by Mr. Yarrel, that the shell is rendered more brittle by the process of hatching, during which the egg of the common fowl loses on an average eight grains a day, the moisture being partly evaporated and partly absorbed, and the lining membrane at the same time becoming partially separated +.

Eggs fractured by the included Chick.

Though the fracture of the shell usually extends round the whole circumference, yet the chick is sometimes contented with performing only about three-fourths of the task. When this has been done, the bill is not required to complete the separation, which is effected more easily and speedily by pushing with the whole mass of its body, using the feet as a lever. By thus continuing to push the body forwards, a movement which is frequently repeated, the chick gradually raises the upper portion of the shell, and at length tears all the fastenings; and if any part hold out, that becomes a sort of hinge which permits the lid, as we may call it, to be thrown on one *Réaumur, as before. Zool. Journ. ii. 436.

side. When the upper portion is wholly detached, it is sometimes thrown to a considerable distance; but it often happens also that it is thrown into a very singular position, and is found placed within the other portion, as one cup may be set within another. This circumstance has been observed to arise from the chick, just escaped, having the upper portion of the shell immediately before him, and pushing it back with his feet into the under portion without any necessity or design. "A young duckling," says Réaumur, "which I observed just as it was striving to separate the two parts of the shell entirely, showed me that it had recourse, in order to this, to methods like those used by chickens and probably by all other birds for the same purpose. The duckling's shell was at most fractured in twothirds of its circumference, but the fracture being wide suffered me to see that the bill was under the right wing, while the little creature was lifting at the forepart of the shell on the side where it did not resist, because there all its fastenings were broken, and by these means it forced the shell to break on the side where it was yet entire."

Positions of the Shell after the escape of the Chick.

"When the chick," Réaumur continues, "has at length been able to turn up or heave off sufficiently the forepart of the shell to procure itself a door, it

stretches out its feeble legs, which are yet insufficient to carry it. Being then entirely or almost out of the shell, it draws its head from under the wing where it had hitherto been thrust, stretches out its neck, and directs it forward, but is not strong enough for several minutes to raise it. Upon seeing for the first time a chick in this condition we are led to infer that its strength is exhausted, and that it is ready to expire; but in most cases it recruits rapidly, all its organs gather strength, and in a very short time it appears quite another creature. After having dragged itself on its legs for a little while, it becomes able to stand on them, to lift up its neck, to bend it in various directions, and finally, to hold up its head. The feathers are at this period only fine down; and as they are wet with the fluid matter of the egg, the chick appears almost naked. By the multitude of their branches these down feathers look like so many minute shrubs; yet when those branches are wet and sticking to each other, they take up very little room, but as they dry they become disentangled and separated. The branchlets, plumules, or beards of each feather are at first enclosed in a membranous tube, by which they are pressed and kept close together; but as soon as this dries it splits asunder, an effect which is also aided by the elastic springs of the beards themselves causing them to recede and spread about. When this is accomplished, each feather extends over a considerable space, and when they all become dry and straight, the chick appears completely clothed in a warm vestment of soft down*.'

It would not be according to the usual course of nature unless the greater number of eggs sat upon proved fertile; but circumstances, many of them unintelligible to us, occur during hatching, which render * Oiseaux Domestiques, as before.

the eggs abortive: and there is scarcely an instance of a hatch of eggs that will not afford a greater number of chickens, if a little artificial assistance be afforded. Some of the chicks, for instance, are weak; while others, though not wanting in strength, still meet with more resistance than they can overcome from the shell or its membrane; and others again, though sufficiently strong, and enclosed in a shell and membrane of the usual thickness and consistence, are unable to effect an exit, even when an aperture is made for them, in consequence, it would appear, of some unknown cause depriving them of the power of making the circular revolution on their own bodies, which, remaining in the same position, stick to the shell.

In order to understand how a chick may be thus glued to its shell it will be necessary to recollect, that between its body and the lining membrane is the white of the egg, or glairy adhesive fluid, which, by drying, becomes a sort of cement, very apt to cause the feathers to adhere to the membrane with which they are in contact. The chick of an egg which has been subjected in artificial hatching to a temperature too high is in the most danger of such an accident; though it seldom happens before it has ́made a pretty large breach in the place first chipt, and has also rent the membrane, after which operations it remains a good while at rest. The air introduced through this rent soon changes into a hard tenacious glue the fluid white next the margin of the aperture, as well as to some distance inward; so that when the chick is desirous of returning to its task it can only peck at the same place, being held fast from moving its body by the glue. Its attempts pull the feathers, and make it squeak; and from its efforts being more and more painful, the desire to move is abandoned. Under such circumstances the chick, if un

assisted, must die, and hence it may not be useless to point out the indications by which this state of things may be recognised. Whenever, then, a considerable fracture of both the shell and the membrane is observed to remain for five or six hours without enlargement, and at the same time the margin of the membrane is perceived to be hard and dry, with perhaps some feathers sticking to it, it will be indispensable to liberate the chick by breaking the shell very gently with a key or some such instrument, and by cutting the membrane with the points of a pair of scissors. The operation, though painful to the chick, does not prove mortal, for it is no sooner freed than it exhibits as much vigour as any other chick of its age.

In the case of a chick not having sufficient strength to break through the shell, the indication will be a slight chip appearing and continuing for several hours without either being extended or the membrane rent. Here it will be requisite to lend assistance, as in the former case; and if it come not too late, as soon as the chick is exposed to the air, it will pull out its head, stretch its neck, and endeavour to get out of the shell.