The _Megatherium_ was nearly as big as an elephant, and its skeleton, though so much larger, is very similar to those of the small sloths of present-day South America. Its teeth also are very much like theirs. But whereas the living sloths climb trees, as they have learnt to do, the _Megatherium's_ method was more primitive though quite as effective. It stood on the ground and pulled the trees down in order to eat the young branches. The _Mylodon_, which lived at the same time, was not so big, and its habits were similar. It had a number of little bony pieces scattered in its skin in the region of the back, like the pieces forming the bony case of the ancient armadillos; but the pieces in this case were not closely fitted together. It was supposed that the _Mylodon_, like all the peculiar gigantic animals of South America, had become extinct as long ago as the Mammoth (of which we shall say more presently) or of the woolly rhinoceros which used to haunt Fleet Street. All these extinct South American animals were distinguished by peculiarly shaped teeth, and had no teeth at all in front. They are called, therefore, _Edentata_, and their representatives to-day are much smaller. But some years ago Dr. Nordenskjold, a Scandinavian traveller, while exploring in Patagonia, found a vast cavern called the _Ultima Speranza_ cave, on the western coast. From this cavern the settlers who lived close by had removed an enormous piece of skin covered with greenish-brown hair, and studded on its inner side with little knobs of bone. The skin was dry but sound. When it was placed in water it gave out a smell which, though unpleasant, was very interesting, for it showed that the animal which had worn it could not have been dead thousands or even many hundreds of years. It was, in fact, evidently a piece of the skin of a _Mylodon_, which had survived in this region until modern times. Further explorations were made in the cavern by Dr. Moreno, of La Plata, and other naturalists, and an immense quantity of bones was obtained, and more portions of the skin of _Mylodon_ with the hair on. The cavern had been inhabited probably several centuries ago by Indians, for human bones and weapons were obtained. The remains of as many as twenty _Mylodons_ have been obtained from the cavern, and many of the bones are cut or broken in a way which leads us to suspect that the human inhabitants of the cave cut up the dead _Mylodons_ for food, and split their bones to obtain the marrow! Some of the _Mylodon_ bones, skulls, jaw-bones, leg-bones, etc., are smeared with blood and have pieces of cartilage and tendon attached. There are other evidences which go to show that the Indians may have kept the _Mylodons_ alive in the cave and fed them with hay brought from the outside. Anybody who would care to see the last of the great extinct animals can inspect some of these remains at the museum in Cromwell Road, London.