Nevertheless, in tree-life and in the air it is the turn of the _insect-eaters_ to claim the advantage. It is true that the insect-eating Bangsrings,[148] which scamper up the trees in Sumatra and South-East Asia, and were long mistaken for squirrels, are a small family and not of much importance; but what shall we say to the Bats, the only true flying milk-givers? Or what, again, to that curious animal the Colugo or Flying Lemur of the Malay Islands, which belongs to the insect-eaters, and yet has some points like marsupials, some like fruit-bats, and some like the true lemurs? This strange creature, which seems like the remnant of some branch-line from very ancient times, climbs the tree like a squirrel by means of its claws, and then spreading out its limbs displays a broad membrane (see Fig. 60) stretching not only along its sides but across its tail, and from the front of the arms to the neck as in bats, and so sails down from one tree to another. The mother, which Mr. Wallace examined, nurses the little one on her breast just as the lemurs do, while large folds of her skin protects the small, bald, naked little creature, something after the manner of an imperfect pouch. Lastly, while they sometimes feed on insects, the chief diet of these colugos is fruit, like the lemurs, to which group they were once supposed to belong. * * * * * But of all modified insect-eaters the most extraordinary are the Bats, which are so different from all the others that they have been placed in a distinct order[149] of their own. Imagine a little creature about three inches long, with a body something like a shrew, large ears, a protruding snout, and plenty of sharp teeth (see Figs. 61 and 62). Let it have a breast bone projecting more than in most milk-givers, and covered with a large mass of muscle as in birds, fitted to move the wings, but having nipples to suckle its young. Let it have large shoulder-blades and collar-bones, a strong upper arm, a very long lower arm (_fa_, Fig. 61), and four immensely long fingers to its hand (_ha_), and a short clawed thumb (_t_). Let its hind legs be short and weak, with a long spur behind the heel (_h_) of its five-toed feet, and finally let the skin of its body grow on over the arms and long fingers, filling in the space between the elbows and the neck in front, and stretching away behind, over the legs down to the ankle, and on behind the legs, so as to enclose the tail. This skin growing from the back above, and the under part of the body below, will enclose the bones of the arms, hands, and legs, like a kite with calico stretched on both sides (see Fig. 56, p. 220), and when the long fingers are outspread and the legs opened, no limbs will be seen, but only a small body and head, with an immense expanse of skinny wing, from which the short clawed thumbs and the four toes of the feet stick out before and behind. [Illustration: Fig. 61. Skeleton of a Bat.