The aye-aye is about as big as a rather small cat, and its great bushy tail is longer than its head and body put together. It is not a common animal, even in Madagascar, and its name of aye-aye is said to have been given to it on account of the exclamations of surprise uttered by the natives when it was shown to them for the first time by a European traveler. But it is more likely that the name comes from the cry of the animal, which is a sort of sharp little bark twice repeated.
Strange to say, the natives of Madagascar are much afraid of the aye-aye. Of course it cannot do much mischief with its teeth or claws; but they seem to think that it possesses some magic power by means of which it can injure those who try to catch it, or even cause them to die. So that they cannot be bribed to capture it even by the offer of a large reward. Sometimes, however, they catch it by mistake, finding an aye-aye in a trap which has been set for lemurs. In that case they smear it all over with fat, which they think will please it very much, and then allow it to go free.
The aye-aye is seldom seen in captivity, and when in that state it sleeps all day long.
CHAPTER IV
THE BATS
Next in order to the monkeys come the bats, the only mammals which are able to fly. It is quite true that there are animals known as flying squirrels, which are sometimes thought to have the power of flight. But all that these can do, as we shall see by and by, is to take very long leaps through the air, aided by the curious manner in which the loose skin of the body is fastened to the inner surface of the legs.
How Bats Fly
Bats, however, really can fly, and the way in which their wings are made is very curious. If you were to look at a bat's skeleton, you would notice, first of all, that the front limbs were very much larger than the hinder ones. The upper arm-bone is very long indeed, the lower arm-bone is longer still, and the bones of the fingers are longest of all. The middle finger of a bat, indeed, is often longer than the whole of its body! Now these bones form the framework of the wing. You know how the silk or satin of a lady's fan is stretched upon the ribs. Well, a very thin and delicate skin is stretched upon the bones of a bat's arm and hand in just the same way. And when the little animal wants to fly, it stretches its fingers apart, and so spreads the wing. When it wants to rest it closes them, and so folds it against its body.
Then you would notice that a high bony ridge runs down the bat's breast-bone. Now such a ridge as this always signifies great strength, because muscles must be fastened at each end to bones; and when the muscles are very large and powerful, the bones must be very strong in order to carry them. So, when an animal needs very strong breast-muscles, so that it may be able to fly well, we always find a high bony ridge running down its breast-bone; and to this ridge the great muscles which work the wings are fastened.