Shay Stockdill, age 11, of Jackson, Miss., for a question:

How does a fish breathe?

If you were a fish and had brains enough to talk, you might ask, "How do people breath?" For getting oxygen from the water is just as natural to a fish as getting oxygen from the air is to us. It seems a pity that we cannot share tricks and both get oxygen from air or water, As it is, only the amphibians can do this with their marvelous skins;

We use our lungs to take in oxygen from the air and the fish uses his gills to take in oxygen froze the water. And, strange to say, there is not a great deal of difference between gills and lungs. As you know, your lungs are deep inside your chest. You take in air through the nose arid it goes down to the lungs through a series of pipes.

The fish, of course, does not breathe through his nose and his gills are situated where you would expect his ears to be. In fact, the round gill covers which protect the gills might be mistaken for a pair of ears. As you watch him, he is forever opening and closing his mouth. No, he is not drinking all that water. He is breathing it. He must keep a constant supply of water coming to his gills dust as you must keep a steady supply of air coming t o your lungs,

The lungs are a spongy mass of tissue riddled with tiny pockets. Countless tiny blood vessels come so near to the surface that the blood is almost in direct contact with the air which fills the little pockets. When certain blood cells come close enough to the air, they go into action.. These cells carry particles of carbon dioxide, the waste product which they have picked up on their trip around the cells of the body, When they get to the surface of the lungs, they give up this carbon dioxide and grab themselves some oxygen.

The gills of a fish look like fine fringes of tissue. As in our lungs, the blood vessels come very close to the surface, close enough for the blood cells to make the same kind of swap of carbon dioxide for oxygen. Yes, the fish needs oxygen to keep his body processes going dust as we do. His body processes also give off waste carbon dioxide and his circulating blood carries this waste to his gills.

These two opposite stories are alike in another respect. Perhaps you have wondered where all the oxygen we breathe comes from. Well, the plants take the carbon dioxide we breathe out, use the carbon dioxide and return fresh oxygen to the air. The same so called oxygen cycle goes on in the world of the fishes. Sea weeds and all sorts of water plants use the carbon dioxide breathed out by the fishes and return fresh oxygen to the water.