Two kinds of chimpanzees are known, namely the common chimpanzee, which is by far the more plentiful of the two, and the bald chimpanzee, which has scarcely any hair on the upper part of its head. One very intelligent bald chimpanzee was kept in Barnum's menagerie, and was even more clever, in some ways, than "Sally" herself. THE GORILLA Larger even than the chimpanzee is the gorilla, the biggest and strongest of all the apes, which sometimes grows to a height of nearly six feet. It is only found in Western Africa, close to the equator, and has hardly ever been seen by white travelers, since it lives in the densest and darkest parts of the great forests. But several gorillas--nearly all quite small ones--have been caught alive and kept in captivity in zoos, where, however, they soon died. One of these, named "Gena," lived for about three weeks in the Crystal Palace, near London. She was a most timid little creature, and if anybody went to look at her she would hide behind a chimpanzee, which inhabited the same cage, and watched over her in the most motherly way. Another, who was called "Pongo," lived for rather more than two months in the London Zoo, and seemed more nervous still, for he used to become terrified if even his keeper went into the cage. But when the animal has grown up it is said to be a most savage and formidable foe, and the natives of Central Africa are even more afraid of it than they are of the lion. Like most of the great apes, the gorilla has a most curious way of sheltering itself during a heavy shower of rain. If you were to look at its arms, you would notice that the hair upon them is very thick and long, and that while it grows _downward_ from the shoulder to the elbow, from the elbow to the wrist it grows _upward_. So when it is caught in heavy rain, the animal covers its head and shoulders with its arms. Then the long hair upon them acts just like thatch and carries off the water, so that the gorilla hardly gets wet at all. When the gorilla is upon the ground it generally walks upon all fours, bending the fingers of the hands inward, so that it rests upon the knuckles. But it is much more active in the trees, and is said to be able to leap to the ground from a branch twenty or thirty feet high, without being hurt in the least by the fall. THE ORANG-UTAN