Jimmy Wessman, &ge 7, of Woodbury, Minn., for his question:

HOW DO FINGERNAILS GROW?

Would you believe that the hoofs of animals and also horns, claws and talons are made up of the same material that you find in your own fingers and toes? Well, it's true. Deer antlers also fall into the same classification.

Horns, hoofs and nails are all the special growths of the outer skin. The growths are actually made up of hardened skin cells.

Skin below the nail is called the matrix, and here is where growth originates. Near the root of the nail, the cells are smaller and carry less blood. If a nail is torn off, it will grow again if the matrix has not been severely injured. White spots are usually due to bruises, and they will grow out as the nail grows.