Gary spring, age 11, of Spokane, wash.., for his question:

Is it true that coral is a sea animal?

A lump of dry coral looks for all the world like a delicate carving made of stone. And. So it is. But the graceful work was made by small animals that live in the watery world of the blue green sea. The tiny craftsmen soon perish when the stony coral is taken from the water.

It is true that hard masses of coral are made by sea animals  which are also called corals. They belong in the class anthozoa, a word which means the f10ver¬animals. Their first cousins are the pretty sea anemones which look like flower gardens in the tidal pools of tropical seas. Altogether, there are more than 6000 of the anthozoans which, in some way or another, remind us of the world of flowers.

All of them are polyp animals with soft bodies. Each polyp encases a stomach. At one end, it has a round mouth and a fringe of petal like tentacles for waving the water and scraps of food down into the stomach. As a rule, the coral. Polyp is much smaller than the sea anemone. It always builds a hard shelter to protect its soft body, and the sturdy sea anemone does not.

Most of the coral polyps build themselves shelters of limestone. They extract calcium carbonate from the sea water and use it as their building material. Each polyp builds a hard, cup shaped calyx which is just big enough to hold its little body. The floor of the apartment rests on the homes built by other corals, on stones or other hard surfaces under the water.

The walls of the coral apartment taper up to a hole in the roof. The little polyp pokes its mouth and its fringe of tentacles out through this door in the ceiling. The tentacles wave a constant stream of water down into the hungry stomach, and the water carries along scraps of animal. And plant life to be digested.

Many varieties or species of coral contribute to the building of a massive coral reef. Each species repeats the special architecture of its ancestors. The differerit coral formations remind us of trees or shrubs, flovers or foliage. Undcr water, the saving tentacles of the living polyps add petal colors to the stony gardens, but the little sea animals soon perish in the dry air. We are left with an empty apartment house  a piece of story coral which was made by living coral polyps.

Corals extract their building materials from sea water. Most of them build with sturdy limestorie. A few use a tough, pliable material which bends with the tidal waters. Same of these structures sweep back and forth like whips, arid some w&ve gently like graceful fans.