This section is from the "The New Student's Reference Work Volume 5: How And Why Stories" by Elinor Atkinson.
Some of these monkeys have the prettiest homes! They camp out all the year round. They love the dense woods of very hot countries. In the beautiful tropical forests along the Amazon River, in South America, monkeys live in bowers in the trees, among red and green parrots, butterfly orchid blossoms, brilliant birds and insects and flowering vines. They live in thousands of tropical islands in the sea, among palms and fruit trees. But a few are found in colder countries: in Mexico and in the mountains of India, Japan and Northern Africa, and even around the great fortress rock of Gibraltar, in Spain.
No matter how much monkeys may differ in other things, they are all alike in having four hands. The bear, the lion, the elephant, the dog—nearly all the animals you can think of, have four feet. Little girls and boys have two hands and two feet. A foot has a long sole and short toes, usually, and the toes cannot grasp and hold things. A hand has a nearly square palm, fingers much longer than toes, and a thumb. In the best kind of a hand the fingers and thumbs have three joints each, and can all be brought together in many positions, and even closed into a fist. All four of a monkey's feet, that he walks on, are really hands, with grasping fingers and more or less perfect thumbs. That is why a monkey is so clumsy on the ground. Usually he walks on the outside edges of the palms with the fingers and thumbs curled in. This gives him a funny, bow-legged look. But just watch him on a tree or a perch, or clinging to the wires of his cage. He's as much at home in a tree as a bird or a squirrel.
Even if a monkey cannot talk, he can tell you very plainly where he lived when he was at. home—that is, whether he is an Old World monkey from over the ocean, or a New World monkey from South America. The monkeys in a Zoo always come to the netting when visitors appear, for they are very curious and want to see everything that is going on. Besides, they have learned that some 'specially friendly little boys and girls carry bags of peanuts. Select any little fellow who comes up to you and give him peanuts, one at a time, as fast as he can take them. If he is an Old World monkey he will stow those nuts away in cheek pouches like a squirrel. He can put a surprising number away, for those pouches stretch and stretch like little rubber balloons. Look at him carefully. His nose, of course, is flat, but the two holes are near together. And when he goes up to a bar to eat his nuts, he does not use his tail in climbing.
A South American monkey's nostrils are far apart. He has no cheek pouches, but heaps as many nuts as he can carry in his two front arms, as you carry packages. But he can keep other monkeys from taking his nuts when he climbs, for he uses his long, curly-tipped tail for a fifth hand. With five hands for grasping the South American monkey is a wonderful trapeze performer. The tree-squirrel climbs faster, the flying squirrel leaps farther, the bat clings better with his wing-hooks, but no other animal can climb, leap and swing, and go across a wide forest, forty feet from the ground without once coming to the earth. The acrobat of the animal world, he seems to be made up of wire springs that are tireless.
The South American monkey that you will see oftenest with the organ man is a small, rusty brown animal about as big as a toy terrier. He has a curved hair-covered tail, good thumbs, a rather pleasant whistling chatter, and a care-worn anxious face, as if he expected nothing in life but bad news. He is bright and obedient, so he soon learns his tricks and performs them willingly. He likes to ride on a dog's back, his master's shoulder or the barrel organ. Another favorite of the organ man's is the Capuchin monkey. You may know him by the queer way in which the hair grows around his face like a hood or Capuchin monk's cowl.
Sometimes in school you learn a rule, and then the teacher will tell you that there are times when the rule doesn't work. The marmoset, the smallest and prettiest of all South American monkeys, cannot use his tail in climbing. When children see the marmoset they always cry: "Oh, what a little dear!" He is no bigger than a chipmunk. He is only eight inches long, with a furry body and a foot-long bushy tail that he carries like a plume. If it wasn't for his almost human little face and hands, and his wing-like, tufted ears, you might think him some kind of squirrel.
There is a squirrel monkey from South America only a little larger than his nut-cracking namesake. He has a gray face and a black nose, but has long hind legs so he leaps something like a kangaroo. When he is happy he shows it by grinning, and when he is hurt tears come into his eyes. In his home in the Amazon forests it rains torrents sometimes, as if the bottom had fallen out of the clouds. When caught in such a storm, a troop of these squirrel monkeys huddle together in the thickest tree they can find, and put their tails around each others' necks for company and comfort.
These marmosets and squirrel monkeys have some of the noisiest neighbors—the howling monkeys. They begin howling at sunrise, keep it up until the next sunrise, and then take a fresh start. The woods ring and echo with their howls. They travel all the time through the high branches of the trees, the males leading, and the mother monkeys following, each with one or two babies clinging to her neck with fingers and tails. They swing by their tails and catch the next limb with a hand. The brown howler is bad enough, but the red howler makes the night hideous with his cries. They screech as if all the animals in the forest were eating each other up. Some zoos won't have Little-old-man-howler, as he is called, at all.