“Wings, real wings, perfectly adapted to flying, are the bat’s most striking feature. How can a mammal, an animal whose general structure is that of a dog or a cat for example, possess the flying-apparatus of a bird? How can two organs so entirely different be combined? In the bat’s wing, my children, we find an admirable example of the infinite resources at the command of the Creator, who, without adding to or subtracting from the fundamental plan, has adapted the same organs to the most widely different functions. The fore feet of mammals—of the dog, or the cat we will say—are changed into wings in the bat without the addition or the loss of a single part in this incredible transformation. More than that, the human arms, our arms, children—are there represented, piece by piece, bone by bone. You all look at me as if you did not believe it, unable to understand how there can be anything in common between our arms and a bat’s wings.” “The fact is,” Jules confessed, “it takes all my faith in your words to make me admit that there can be the least likeness between a man’s arm and a bat’s wing.” “I do not propose to make you admit it because of your faith in me; I propose to prove it to you. Follow along your arm so as to grasp the demonstration better. “From the shoulder to the elbow the framework of the human arm consists of a bone known as the humerus. From the elbow to the wrist there are two bones of unequal size running side by side the whole length. The larger is the cubitus, the smaller the radius. Then comes the wrist, composed of several little bones which I will not now describe. Next is the palm of the hand, its framework formed of a row of five bones almost alike and each serving to support a finger. Finally, each finger contains a succession of small bones called phalanges, of which the thumb has two, and all the others three each. I will add that two bones serve to attach the arm to the body. One is the shoulder-blade, a broad triangular bone situated on the back behind the shoulder; the other is the collar bone, slender and curved, situated in front and extending from the shoulder to the base of the neck. Those are the collar-bones that you can feel with your hand at the right and left above the breast.” While thus enumerating the parts of the arm, Uncle Paul guided the hand of each listener and made it feel the several bones as they were named. Emile had some difficulty with the learned terms “humerus” and “cubitus,” which he now heard for the first time; nevertheless, by paying close attention he found that he could easily remember them. When the boys had all learned the name and the position of each bone in the human arm, their uncle continued: “Now examine with me this picture of a bat’s skeleton. The bone marked o is the shoulder-blade. As with us, it forms the back of the shoulder, and it is triangular, wide, and flat.”