of somewhat wrinkled skin, having a colored tint. The wrinkles are due to the presence of sebaceous glands which secrete a fatty substance for the protection of this organ during the nursing period. In the young woman this area is usually either pink or crimson, and darker tinted in brunettes than in blondes. With the beginning of pregnancy, the tinted surface enlarges and deepens in color, becoming brownish, which remains permanent after the birth of the child.
The structure of each breast is made up of fifteen or twenty lobes or divisions, separated by partitions. Each lobe is a distinct milk-producing unit, and has a tube going direct to the nipple which acts as the outlet for the milk secreted in the individual lobe.
THE INTERNAL SECRETIONS
In the previous chapter, reference was made to the secretions of the endocrine or ductless glands in men. The system as a whole, excepting only the sexual unit, is quite identical in the two sexes. The internal secretion of the male's sexual glands (testes) has its analogy in the female in the internal secretion of the ovaries.
The ovaries, in addition to their procreative function which has been described, produce an hormone, or internal secretion, which directly enters the blood stream, and in this way exercises a profound influence over the whole organism. As a matter of fact, this internal secretion is more vital, at least to the individual, than the external secretion, or the process of ovulation.
A woman may be barren—that is, incapable of bearing children—from various causes, so that the process of ovulation is interfered with or does not take place, and still be a fine physical and mental type of womanhood.
