ADRENAL EXCESS
The converse of adrenal insufficiency, that of adrenal excess, also exists. In certain types of the middle-aged, a high blood pressure, accompanied by a great capacity for work, has been shown to be associated with hypertrophy of the cortex. In women, there is a degree of masculinity, as the adrenal in women makes for masculinity, neutralising more or less the specifically feminine influences of the internal secretions of the ovary. Such women possess a vigor and energy above the normal, and command responsible positions in society, not only among their own sex, but also among men. They are the ones who, in the present overturn of the traditional sex relationships, will become the professional politicians, bankers, captains of industry, and directors of affairs in general.
THE GONADS
(Sexual, Puberty or Interstitial Glands)
The gonads is the name applied to the generative or reproductive glands considered collectively. In the male, they are the testes; in the female, the ovaries. They are, therefore, sometimes called the sexual glands. As they possess definite canals for the removal of their gross secretion, the specific reproductive cells, ova or spermatozoa, to a surface of the body, they are first of all glands of external secretion. But they have been also found to hold secretory cells not concerned with the making of the reproductive corpuscles, but, as all the evidence indicates, with the manufacture of an internal secretion. These interstitial cells form the interstitial gland. A classic example of a gland of internal secretion lodged in the interstices of a gland of external secretion is thus furnished by the gonads.
ORIGIN OF SEX TRAITS
The history of sex goes back far in the scheme of life. The immortality of the ameba was at one time one of the indisputables of biology. Then some observations were made which threw doubt upon a long accepted fact, now declared a dogma. Lately, opinion has veered back to immortality. But in the case of a close relative of the ameba, the one-celled animal known as the paramecium, union with another paramecium, true conjugation, has been proved necessary to prevent death sooner or later. Sex here appears in its most primitive form, on the basis of exchange of necessary materials, between individuals to prevent death, their own having been, so to speak, worn out, in the course of metabolism.
Specifically different sexes come later, when mortality is a universal fate, as a means of rebirth and escape from death. Then the sexes develop their latest function, most prominent among the younger vertebrates, of acting as nature's most potent method of variation and differentiation. In the pursuit of the different, nature has exalted sex, and the intensity of the sex life. As far as the preservation of a species is concerned, and the reproduction of the individual, the asexual methods, budding, for example, would have done well enough. But when it comes to enacting a different individual apart from the effects of environment, sex stands out as the favored method of Life.
The development of the sexes and the sexual life brought a new element of conflict into the living world. Before the advent of the sexes the conflict was essentially for the means of existence, food alone. But with the sexual life came a conflict for sex pleasure, a competition among members of the same species for the same individual as their sex partners. The result was the introduction of a factor in evolution which Darwin examined so closely in the "Descent of Man."
The sex conflict has been the cause for the origin and the survival of certain physical and mental traits, helpful in sex attraction, sex combat, the growth of the embryo, and the nutrition and safety of the young of a species,—in short, the whole process of sexual selection. The proportions of the skeleton, the distribution of hair and fat, the construction of organs of attack and defense, the color of the skin, the cyclic processes of preparation for impregnation, the oestrus or heat period in animals, the menstrual period in the human being, the psychic reactions to danger and combat have all been thus determined. That man is bearded while woman is not,—that woman has potentially functional breasts while man has not,—the aggressive pugnacity of man contrasted with the more passive timidity of woman, have all been evolved in the sex struggle, surviving because most effective in that struggle. These so-called secondary sexual characteristics are an expression of the influence of the internal secretion of the gonads, or the interstitial glands. Some call them puberty glands, because their ripening initiates puberty.