Page:Popular Science Monthly Volume 5.djvu/287

Rh era. Were changes of structure really as rapid at this period, it would imply vital depression, just as we see it in plants and animals taking on rapid growth, and just as we see impaired mental and bodily energy follow sudden and excessive exercise of any organ in a member of the human family. Yet at puberty the opposite occurs. Women are never so hopeful, buoyant, and strong, as at the beginning of healthy ovulation.

Analogy furnishes strong arguments in favor of the early and gradual preparation of the system generally for the ovarian function. Mammary enlargement antedates functional activity by months in cases of gestation. Here is a comparatively simple act, that of glandular secretion, preceded by elaborate structural preparation. In the sexual cycle of organs the mammæ act a subordinate part; yet in this region, in the two sexes during childhood, the first sexual characteristics may be detected in the well-developed. This is an interesting and most significant fact, and one that renders it highly improbable that pelvic enlargement is postponed to the puberic age, and coincides with many other facts which show that sexual evolution is a simultaneous movement toward completion by all the organs involved.

The commencement of the ovarian function is not the only crisis through which woman has to pass. There are two dentitions, each of which is a critical period. It is, I think, safe to say that the diseases incident to dentition destroy more human lives three to one than the diseases of ovarian function. Dentition is a process preceded by elaborate anatomical preparation, and furnishes the strongest analogous proof of gradual and persistent sexual development. Teeth which appear at the fifth to the sixth months of life, are preceded by anatomical changes begun as early as the sixth week of fœtal life. Teeth which are to make their appearance at the fifth to the ninth years of life are in a preparatory state at the seventh month after birth; and teeth which make their eruption between the seventeenth and twenty-first years are in a recognizable state of growth at the sixth year of age. Here is a most elaborate preparation for function, a slow and ceaseless building up, with—in a state of health—no paroxysmal outbreak, either in the growth or completion of function. It is equally true that the organs within the pelvis which characterize sex can be traced to a fœtal origin, and, during the months of infancy and years of childhood, they exhibit the same process of structural evolution. Paroxysm in the process of dentition is a disease, and it is equally a morbid act in the development of sexual maturity. Ovulation does not induce a greater change in the system and habits than does dentition. This may appear at the first glance to be an unwarranted assertion. But observe the change in the life and habits of the little human animal at the eruption of the deciduous teeth. After subsisting upon a single article of diet it becomes omnivorous: from entire dependence upon others, it has reached a certain amount of