Scott Wiegand, age 11, of San Diego, California, for his question:

What use are tonsils?

Some of us suspect that tonsils were added just to inflict sore throats on innocent children. But actually this is far from the truth. The tonsils belong to the lymphoid system that does its best to fight enemy germs. They are fleshy sacs of lymphoid tissue, teeming with white blood cells, whose duty it is to protect the body from invading bacteria.

All sorts of bacteria enter the mouth and nose and a few types produce infections. Most of them are destroyed by white blood cells in the tonsils. But sometimes the task is too great and the tonsils themselves become infected. This is when we get the notion that the hardworking tonsils are useless extras that cause feverish sore throats. This happens only when things get too much for them. Usually they work successfully, day and night, to fight infections.