In the case of men of strong sexual passions the congenital
hairs shed the sooner, while the hairs of the after-growths are the
quicker to come. When men are afflicted with varicose veins they are
less inclined to take on baldness; and if they be bald when they
become thus afflicted, they have a tendency to get their hair again.

If a hair be cut, it does not grow at the point of section; but it
gets longer by growing upward from below. In fishes the scales grow
harder and thicker with age, and when the amimal gets emaciated or
is growing old the scales grow harder. In quadrupeds as they grow
old the hair in some and the wool in others gets deeper but scantier
in amount: and the hooves or claws get larger in size; and the same is
the case with the beaks of birds. The claws also increase in size,
as do also the nails.