cheval-de-frise of sharp spikes toward any animal that may present itself as an enemy. Another peculiarity is the power possessed by these creatures of rolling themselves into a round ball, by placing the head on the breast, drawing up the legs, and curling the body firmly round the members. By this posture the hedgehogs render themselves invulnerable to almost any animal that may attack them. . . . When in this curious attitude, the hedgehog can not be unrolled by main force, as long as any life remains in the body, for there is an enormously developed muscle, with a very thick margin, which spreads over the back and round the sides, and which, when contracted, holds the creature in so firm an embrace that it will be torn in pieces rather than yield its point."
The spines of this animal are about an inch long, and naturally lie flat on the back, directed toward the tail. But by a peculiar arrangement they are erected when the owner coils himself. In shape the spine "is not unlike a large pin, being sharply pointed at one extremity, and furnished at the other with a round, bead-like head, and rather abruptly bent near the head. If the skin be removed from the hedgehog, the quills are seen to be pinned, as it were, through the skin, being retained by their round heads, which are acted upon by the peculiar muscle which has already been mentioned.
"Protected by this defense, the hedgehog is enabled to throw itself from considerable heights, to curl itself into a ball as it descends, and to reach the ground without suffering any harm from its fall. A hedgehog has been seen repeatedly to throw itself from a wall some twelve or fourteen feet in height, and to fall upon the hard ground without appearing to be even inconvenienced by its tumble. On reaching the ground, it would unroll itself and trot off with perfect unconcern."
The quills upon the "fretful porcupine" are several inches in length. The absurd belief that this animal could throw its quills at an enemy, after the fashion of a lance, arose from the following facts: "Their hold on the skin is very slight, so that, when they have been struck into a foe, they remain fixed in the wound, and, unless immediately removed, work sad woe to the sufferer. For the quill is so constructed that it gradually bores its way into the flesh, burrowing deeper at every movement, and sometimes even causing the death of the wounded creature. In Africa and India leopards and tigers have frequently been killed in whose flesh were pieces of porcupine-quills, that had penetrated deeply into the body, and had even caused suppuration to take place. In one instance a tiger was found to have his paws, ears, and head filled with the spines of a porcupine which he had vainly been endeavoring to kill. . . . If irritated or wounded, the porcupine becomes at once a very unpleasant antagonist, as it spreads out its bristles widely, and rapidly backs upon its opponent."
Many small creatures are undoubtedly protected by offensive fluids