THE OVUM. The Ovum, or human egg, is a small spherical body, measuring from one two-hundred-and-fortieth to one one-hundred-and-twentieth of an inch in diameter. It has a colorless transparent envelope, the latter enclosing the yolk which consists of granules or globules of various sizes embedded in a viscid fluid. In the center of the yolk is found a very small vesicular body consisting of a tenuous transparent membrane, which is known as "the germinal vesicle;" this, in turn, contains a very tiny granular structure, opaque, of yellow color, known as "the germinal spot." When the time is reached in which the ovum or egg is to be discharged, the Graafian follicle becomes enlarged by reason of the accumulation of the fluids in its interior, and exerts such a steady and increasing pressure from within, outward, that the surrounding tissue yields to it, and it finally protrudes from the Ovary, from whence it is then expelled with a gush, owing to the elasticity and reaction of the neighboring tissues. Following this rupture there occurs an abundant hemorrhage from the vesicles of the follicle, the cavity being filled with blood, which then coagulates and is retained in the Graafian follicle. The formation and development of the Graafian follicle begins at puberty and continues until the menopause or "change of life" of the woman. Many follicles are produced, but many do not produce ova, and so gradually atrophy. The ripening and discharge of the eggs produce a peculiar condition of congestion of the entire female sexual organism, including the Fallopian Tubes, the Uterus, the Vagina, and even of the Vulva, which results in a condition of Sexual Excitement. Among the lower animals the female will allow the male to approach her for copulation only at this period, this being the time when the egg is ready for fertilization. When the female infant is born, her Ovaries contain the germs of about 100,000 ova. The greater portion of these, however, disappear, until at the time of her puberty the number of germs of ova contains only about 30,000 ova. This number is far more than the woman will ever need, and is Nature's provision against diseased portions of the Ovaries, accidents, etc. Only one ovum ripens and matures each month from puberty until menopause, so that the woman really requires only about 300 to 350 ova on the average. This liberality on the part of Nature, however, does not begin to approach her lavishness in the case of seed of the male, for in his case while only one spermatozoon is required to fertilize an ovum (and in fact only one is permitted to do so), we find that in each normal act of ejaculation of semen by the male over 250,000 spermatozoa are projected.