The African elephant (as could be seen by comparing the small one living in Regent's Park with its neighbours) has a sloping forehead graduating into the trunk or proboscis, instead of the broad, upright brow of the Indian. He also has very much larger ears, which lie against the shoulders (except when he is greatly excited) like a short cape or cloak (see Fig. 7). These great ears differ somewhat in shape in the elephants of different parts of Africa, and local races can be distinguished by the longer or shorter angle into which the flap is drawn out. The grinding teeth of the two elephants differ very markedly, but one must see these in a museum. The grinders are very large and long (from behind forwards), coming into place one after the other. Each grinder occupies, when fully in position, the greater part of one side of the upper or of the lower jaw. They are crossed from right to left by ridges of enamel, like a series of mountains and valleys, which gradually wear down by rubbing against those of the tooth above or below. The biggest grinder of the Indian elephant has twenty-four of these transverse ridges, whilst that of the African has only eleven, which are therefore wider apart (see Fig. 8). An extinct kind of elephant--the mastodon--had only five such ridges on its biggest grinders, and four or only three on the others. Other ancestral elephants had quite ordinary-looking grinders, with only two or three irregular ridges or broad tubercles. Both the Indian and African elephant have hairless, rough, very hard, wrinkled skins. But the new-born young are covered with hair, and some Indian elephants living in cold, mountainous regions appear to retain a certain amount of hair through life. The mammoth (which agreed with the Indian elephant in the number of ridges on its grinders and in other points) lived in quite cold, sub-Arctic conditions, at a time when glaciers completely covered Scandinavia and the north of our islands as well as most of Germany. It retained a complete coat of coarse hair throughout life. The young of our surviving elephants only exhibit transitorily the family tendency.