The use of this loose skin will be very evident to any one who will take the trouble to watch the great Cats playing together at the Zoological Gardens. They are continually scratching one another, but the loose skin is dragged round by the claws which, in consequence, can get no hold, and do no harm; with a tight skin, on the other hand, the slightest scratch of such a claw as a Tiger’s would cause a serious wound. The looseness of the skin is very evident in the Puma and Jaguar, in which it hangs in a fold along the middle of the belly, like a great dewlap. In the Carnivora the skeleton, or bony framework of the body, attains its utmost perfection, both as a _tissue_ and as machinery. Its tissue is dense, white, and ivory-like, every bone is exquisitely moulded and polished, so that there are few more beautiful objects of study than a well-prepared Cat’s skeleton, and almost none more instructive or better calculated to give an idea of the perfection of “animal mechanics.” The flexibility and strength of the spine, the exquisite fitting of its joints, the small head capable of being turned in almost any direction in the search for prey or the avoidance of danger, the wonderful arrangement of levers afforded by the limbs, which exhibit at once the greatest amount of strength and the greatest amount of elasticity, all combine to fill the mind with wonder and admiration, as great as that excited by the most perfect work of art or the most stupendous phenomenon of inanimate nature. [Illustration: UPPER VIEW OF LION’S SKULL.]