given of women, who, although they had menstruated with perfect regularity, ceased menstruating from the moment that the ovaries had been extirpated by certain surgical operations made necessary by disease. A corroboration of this statement is also the fact that females do not men- struate before ovulation begins, which time is denominated the period of puberty; and cease to menstruate when ovula- tion ceases, which period is called the cliange of life.
The change of life occurs generally between the ages of forty and fifty. This change, or termination of ovulation and of the capability of bearing children, is affected by the time when ovulation first commenced, by climate, and by the habits and constitution of the subject. Thus, the woman in whom ovulation had commenced at the age of ten would cease menstruating five years before the one in whom it commenced at fifteen. And women who are of prudent and healthy habits, of sound and robust constitu- tion, may retain the power of ovulation longer than others, as is recorded of women who bore children at the advanced age of fifty-five and sixty.
In women whose ovaries have been extirpated, the most singular phenomena have been noticed to take place; they menstruate no longer, their breasts dwindle away, their delicate mould and features are lost, and a more sinewy and coarse expression of form and face appear; the soft, melodious voice of woman changes into a strong, harsh, masculine tone.
Menstruation, although a consequence of ovulation, is not necessary to conception; for it is known that women have borne children who never menstruated.