My son is taking organ lessons for this summer. Before the summer classes started he cut his fingernails, which he let grow for almost two weeks. Why do fingernails grow, he once asked me?
The nails are flattened, elastic structures which are relics of claws. They consist largely of compressed keratin, and are in fact greatly thickened areas of the epidermis. The keratin of the nails can absorb large amounts of water, particularly during a warm soak. This is why nails are softer, and much easier to cut, after a bath.
On average, fingernails grow by half a millimetre or so a week; toenails grow a little more slowly. Growth is said to be quicker in the summer than in winter, and is most rapid in the longer digits.
Nails sometimes have white flecks. When i was a little child, i was told that if you have white flecks in your nails, you have many friends. Mine had no white flecks, so I would hide my nails in order not to be tagged as having no friends. How i laughed when i read that the white flecks that sometimes appear in the nails are due to minute air bubbles in the nail structure.