Tina Feese, age 9, of Stevens, Penn., for her question:

HOW MANY KINDS OF MONKEYS ARE THERE?

Some people believe that apes  including chimpanzees, gibbons, gorillas and orangutans  are monkeys. This is not true. Monkeys and apes differ in a number of ways. First of all, apes are more intelligent. Also, most monkeys have tails but none of the apes do. Monkeys are also much smaller animals than most species of apes.

Monkeys rank high on the intelligence scale. They are favorites in zoos around the world but pick the tropic regions of Asia, Africa and South and Central America as their natural homes.

There are about 200 different species of monkeys. Smallest species are the pygmy marmosets which measure about six inches long, not including the tail. At the other end of the scale is the mandrill, a monkey that may grow to be 32 inches long, not including the tail.

Monkeys are placed into two groups:    the New World monkeys and the Old World monkeys. New World monkeys are those found in Central and South America and the Old World monkeys are those living in Africa and Asia.

All New World monkeys have nostrils spaced widely apart while the nostrils of Old World monkeys are close together.

Most kinds of New World monkeys have 36 teeth while all Old World monkeys have 32 teeth, the same number as human beings. New World monkeys can grasp objects with their tails but Old World monkeys are unable to do this.

All New World monkeys are arboreal  that is, they live in trees. Some Old World monkeys, on the other hand, live on the ground while many also live in trees.

All monkeys have long arms and legs that help them climb, leap and run. They can also use their hands and feet to grasp objects, including the branches of trees. They depend more on their eyes than their noses to get information about their surroundings. They can see in depth and distinguish colors. They can judge distances and tell the size, shape and ripeness of food. Monkeys eat grass, leaves, fruit and some insects.

Many kinds of Old World monkeys have cheek pouches like those of hamsters and squirrels. The pouches enable the monkeys to store food temporarily. None of the New World monkeys have these pouches.

Old World monkeys have opposable thumbs, meaning that the thumb can be placed opposite any of the other fingers. This allows the monkey to grasp a tree branch in much the same way that a person grips the handle of a hammer. Most kinds of New World monkeys have thumbs that are only partly opposable.