Deanna Archer, age 11, of Tacoma, Wash., for her question:

WHAT ARE FINGERNAILS

Fingernails, just like toenails, claws and hooves, are produced by the skin.

Nails are actually the flattened claws of the highest order of mammals  the primates which include man, monkeys and apes.

Nails are made of a subsance called keratin, a horny material which protects the digits. They are modified reptilian scales consisting of a hard top plate and a soft under plate.

Fingernails grow from the matrix, the crescent half moon on the nail base, which is formed by the deepest layer of the outer epidermis. They grow about one eighth of an inch per month.