Mary Ann Sauers, aged 11, of Rochester, Td.Y., for her question:

Can all turtles swim?

Turtles and tortoises belong to an armor coated family of reptiles. The tortoises are the land dwelling branch of the family. Some of them never go near the water throughout their whole lives. The giant, 500 pound tortoises of the Galapagos Islands like to congregate in the lush vegetation near springs and rivers. But they won't go into the water of their own accord.

The little desert tortoise of our southwest lives his whole life far from the water. He even perishes when taken to live in damp and humid climates.

The turtles are the water dwelling members of the family. All the turtles are fond of water and all of the turtles are good swimmers. Their limbs are specially adapted for swimming, whereas the legs of the tortoise are suited for walking. Some turtles live almost all their lives in the ocean. Others are fresh water creatures, spending their time in and out of the streams and ponds.