Let us fancy, then, a small boy being turned into a Bat. The first thing that would have to happen would be that his legs would have to be bent at the knees, and shrunk until they were as thin as sticks. Then they would have to be twisted right and left until the knee-caps faced the wrong way about. His arms would have to be shrunk too, and his fore-arms would have to be stretched until they were twice their natural length, and his middle-fingers would have to be about a yard long, and his other fingers nearly a yard long also. His thumb might be left as it was, but it would have to have a strong claw at the end of it. In between his fingers, and joining his arms to his body, and stretching down to his legs, and joining his legs together, there would have to be a web of skin, and then, perhaps, if his chest was brought well forward like a pigeon's, and his head pressed well back until it stopped between his shoulders, he might, if his muscles were strong enough, and the whole of him was light enough, be able to fly. [Illustration: THE NOCTULE One of our largest Bats. He is sometimes more than a foot across the wings, and his brown fur is as velvety as a Mole's--when he feels quite well] [Illustration: LESSER HORSESHOE BAT He is hanging head downwards, and beginning to wrap himself up in his wings before going to sleep] Now about a Bat's eyes. I have already told you that these are very small--at least they look very small in our English Bats--and that it does not seem likely that Bats possess the wonderful eyesight, which one would expect them to have. In some cases the eyes are so curiously placed in the head that the Bat can hardly be able to see straight in front of him at all. In the Leaf-nosed Bats, for instance, you can only just see the Bat's eyes when you look at him full face, because his leaf-nose all but hides them--you can see what I mean from the pictures--and in the case of one rare little bat, the Barbastelle, the eyes are set so far back that part of the ear comes round them like a horse's blinkers; and one can hardly imagine his being able to see much sideways, even if he can see quite well in front. There is just one little thing, however, which I have noticed in a large Bat called the Noctule, and this may mean that Bats have better eyesight than one would at first suppose. The Noctule can make his own eyes "start out of his head," until they seem to be almost twice as large as usual. If all Bats can do this it is quite likely that very few people have seen their eyes properly at all; that is, have seen them as they really appear, when the Bats are chasing moths in the twilight. [Illustration: THE GREATER HORSESHOE--A PIG THAT _DOES_ FLY] [Illustration: THE GREATER HORSESHOE BAT Hanging head downwards. Except when he is flying he always carries his tail cocked up over his back, as you see it.]