The hair of the face in males, and the other terminal hairs in both males and females, is regulated by the sex glands primarily.  In the female, the ovary, that is to say, the interstitial cells of the ovary, inhibit the growth of hair upon the face.  In destructive disease of the ovaries, as well as in other affections of it, hair in the form of moustache, beard and whiskers may appear in female.  That is why in women after the grand sex change of life, the menopause, hair often grows in the typically male regions because of loss of the inhibiting influence of the ovarian internal secretion upon them.  After castration of the ovaries, the same may result.  Removal of the male sex glands, or disturbances of them, will interfere with the proper development of the normal facial hair.  Of the hair of the chest, the abdomen and the back, the adrenals seem to be the controllers.  Adrenal types have hairy chests in males, and hair on the back in females.  They have also a good deal of hair upon the abdomen.  The hair on the extremities varies a good deal with the pituitary.  People with hair upon hands, arms and legs, alone, are generally pituitary, or have a striking pituitary streak in their make-up.

When the adrenals increase in size in childhood, a remarkable triad follows—­general hairiness, adiposity and sexual precocity.  One fact should be noted.  When the adrenals evoke precocity, and an early awakening of the secondary sex characteristics, it is a masculine precocity, and an approximation to the masculine even in females.  There is a definite trend toward an increase of the male in the individual’s composition at the expense of the female.  We shall have to consider this in greater detail when we analyze the internal secretion basis of masculinity and femininity.  In general, the degree of general hairiness is an index to the amount of adrenal influence upon the organism.  All the endocrines which affect the hair growth also act upon the sebaceous glands which oil the skin.

THE EYES

Eyes present clues to internal secretion constitutions dependent upon influences of architecture and function.  The thyroid eye is typical.  It is large, brilliant and protruding.  The individual is “pop-eyed.”  On the other hand, subthyroidized eyes tend to be sunken and lustreless.  The eyes of a pituitary type are either set markedly apart, or close together, with the hair at the root of the nose so prominent as to constitute a separate bridge known as the nasal brow.  The size of the pupil, and its humidity, which have so much to do with the expression of the eye, vary directly with the activities of the driving and checking divisions of the vegetative system, and are a pretty good index as to which, at the time of observation, is predominant.  When the check system is in control, the pupils are large and dilated.  When its antagonist and rival, the drive system, is on top, the pupils are small and contracted.  The reactions of the pupils when charged by strong emotion, like fear or anger, likewise turn upon the status of check or drive internal secretions in the economy of the organism at the time the exciting agent presents itself.