seconds. This air, when it has performed its office, and has been deprived of its oxygen, is expelled in the same manner, but by an inverse mechanism, which is entirely due to the action of the muscles which tend to approximate the ribs to each other. When it is expelled rather briskly, a sort of vibration or hissing is heard.”
The learned zoologists just cited have given some interesting illustrations of the absorbent powers of the intestines of serpents. Their fæcal evacuations afford a singular proof of this; for they present, as it were, the dry extract of the animal swallowed, in an entire state; the parts that could not be dissolved remaining unaltered, and absolutely in the same situation that they occupied in the carcase of the animal before it had passed through the whole length of the digestive tube. If, for instance, a rat has undergone this process, one may recognise in the dry and shapeless mass, the place occupied by the muzzle of the animal, the long whiskers of its cheeks, the down which covered the delicate cartilages of its ears, the hairs of various lengths and colours which correspond with those of the back, the belly, and above all, the tail; and finally, even the claws, which remain in their pristine state of integrity. All that was flesh or soft matter in the body has been completely absorbed; the earthy salt, nevertheless, which gave, by means of its union with the gelatine, consistence to the bones, still indicates by its presence, and especially by its colour, the place they occupied. Dissolution, compression, and absorption, have done their work upon this desiccated mass, which still, however, contains the elements of nourish-
