Mark A. Smith, age 8, of South Windham, Maine, for his question:

Why does a tadpole lose his tail?

As you know, a pretty little tadpole grows up to be a funny frog. The life story of a frog seems very odd because he does not grow up as we do. He hatches from a jellif ied egg, floating in the water. But the baby tadpole does not look at all like his froggy parents. As a matter of fact, he is a very different kind of animal. A frog can breathe air and live on the land. The tadpole has fishy gills for taking his oxygen from the eater. He cannot breathe air so he must live like a fish in the water. For this he needs a tail to swim around.

But his fishy life lasts only a few weeks. As he grows, his body changes and gets ready to leave the water. This remodeling job needs building materials. And since he won't be needing his tail, his body uses this material    and gradually the little black tail disappears. While this is going on, changes are made to create a new way for breathing. The teen age tadpole grows air breathing lungs inside his chest. And gradually, his feathery gills disappear. If all goes well, a newly hatched tadpole may change into a small frog in four to six weeks.