Nancy Karp, age 10, of Horner W. Va., for her question:

Is it true that dolphins lay eggs?

Zoos, it seems, are getting better all the time, and a few marine aquariums display huge sea dwellers in tanks and pools of their natural ocean waters. Here we may see the dolphin, and unless we know better we might mistake the mighty swimmer for a whopping fish.

Not all the creatures that dwell in the deep blue sea are fishes. The lobster and crusty crab are not true fish, and neither is the starfish, regardless of his name. There are also many non fishes at the other end of the size scale. Most of the giant dwellers of the deep are mammals that belong to the same group as the cats and cows.

The largest animal that ever enjoyed life upon our planet is one of these sea going mammals. He is the monster blue baleen whale of the animal order Cetacean. His smaller cetacean cousins include an assortment of dolphins and porpoises. Though they spend all their lives in the water, these splendid animals are air breathing mammals. They can stay below only as long as they hold their breaths. A mother dolphin is no fish; neither does she lay eggs like a fish. Like all mammals she gives birth to live babies and feeds them on mother's milk.

Her family includes the common dolphin and the white dolphin, the bottle nose dolphin and the risso dolphin, the huge and hungry grampus and a dolphin called the pilot whale. The unborn infant may be carried within his mother's body from six to 15 months, depending upon her species. So far as we know, the dolphin calf is always an only child.

The 12 foot bottlenose dolphin may carry her infant for 390 days, and the newborn calf is almost four feet long. The 28 foot pilot whale gives birth to a six foot dolphin calf, usually in the late fall. The calf of the common dolphin is born in summer, and the birth as a rule takes place in deep water. The infant struggles for perhaps 30 minutes to free himself from his mother's body, but the actual moment of birth is very fast. Now comes a risky problem, for Junior must reach the surface to gulp his first breath of air. He can do this under his own power, but his loving mother takes no chances.

She dives under her newborn darling and lifts him up through the water. There, the proud mother and her infant rest and fill their lungs. Junior is ready for his first meal in half an hour, and being a mammal he is fed on mother’s milk. The milk, however, is injected into his mouth, and unlike most mammals the dolphin calf does not have to suck his nourishment.

The cetacean dwellers of the deep share other features with the land dwelling mammals. They are warm blooded animals and highly intelligent. Dolphins wear no furry mammal type coats, and in the water their dark and gleaming skins seem quite bare. Some, however, have a few whiskers and bristles, and the five foot calf of the risso dolphin is likely to enter the world bedecked with a bristly white moustache.