5. The colour of the hair changes in men as they grow old, and the hair becomes grey. This takes place in other animals, but not so remarkably as in the horse. The hair begins to grow white from the extremity. Most white animals are white from their birth, wherefore it is plain that whiteness does not arise from dryness, as some persons suppose, for no animal is born dry. In the exanthematous disease, called whiteness, all the hair becomes hoary; and some patients, who have suffered from illness, after the hair has fallen off on recovery, have regained their dark-coloured hair. Hair which is covered up becomes white more readily than that which is exposed to the air; in man the temples are the first to grow grey, and the fore part of the head before the hind part, and last of all the hair on the pubes. 6. Some of the hair exists on the body at the period of birth, and some appears afterwards. In man alone the hair on the head, eyelashes, and eyebrows exist at birth. The hair on the pubes, in the armpits, and on the chin appear successively after birth, so that the parts on which the hair appears at birth, and those on which it grows afterwards are the same in number. In old age the hair on the head especially is the first to fail, and falls off. This is only in front, for no one ever becomes bald on the back of the head. The smoothness on the crown of the head is called baldness, that upon the eyebrows depilation; neither of these takes place before the commencement of puberty. 7. Children, women, and eunuchs never become bald. If a person be castrated before puberty, the hair which grows after birth never makes its appearance; if after puberty these alone fall off, except the hair on the pubes. Women have no hair upon the chin, excepting a few of those in whom the catamenia have ceased, and the priestesses in Caria: and this appears ominous of future events. Women also have other hair, but not much. There are some persons, both male and female, who from their birth are without the hair which grows after birth; but those persons are barren who have not hair on the pubes. 8. The rest of the hair grows proportionally, either more or less. That upon the head grows the most, then that on the chin, and thin hair most of all. The eyebrows grow so thick upon some aged persons as to be cut off, for they are placed upon the symphysis of the bone; and this being separated in old persons, a more abundant moisture exudes. Those on the eyelids do not grow, but they fall off, when persons come to puberty, and especially in those of warm sexual desires; they become grey very slowly. If the hair is plucked out during the period of growth, it comes again, but not after it has done growing.