The Seminal Vesicle consists of a coeal tube, much convoluted, and lined by a fine honeycomb mucous coat, exactly like that of the gall-bladder. Whether these organs merely lodge the semen, secrete an independent fluid, or both, is undetermined. They often contain spermatozoa, which may have merely moved back from the vas deferens. They are absent in many animals, do not waste after castration, and in the elephant there are seminal reservoirs distinct from them.

The Prostate consists of many ducts opening into the urethra and pouring out viscid mucus, and is chiefly made up of a mingled fibrous and muscular substance, very similar to that of the uterus. The following glands also pour mucus into the urethra-the sinus pocularis, which Weber termed the uterus masculinus, the antiprostatic glands of Cowper, lacunæ, and some branched follicles called the glands of Littre. The urethra, the common urino-genital passage, has been before alluded to. Its posterior curve is equal to of a circle 3 inches in diameter, which is therefore the proper curve for catheters. The spongy body which surrounds it, dilating into the bulb behind, and the glans penis in front, are represented in the foregoing view of the male organs from the perineum.

The Penis is mainly composed of erectile tissue, which

Helicine Arteries ending in smaller vessels.

He

has been described at page 147, but, according to Müller, there are peculiar arteries he termed helicine, from their shell-like curves. believed these were cœcal, and that they only contained blood during erection. Kölliker has found that they are not exactly cœcal, but that extremely fine vessels lead from them. Houston

believed that the erect state of the organ was due to compression of the dorsal vein by a few fibres of the ejaculator seminis, which he called the "compressor venæ dorsalis penis."

Puberty occurs in man about the 14th or 15th year, and is marked by the development of sexual feelings, enlargement of the genitals, and the presence of spermatozoa in the semen. Among other concomitant changes are the growth of hair on the face and pubis, increase in size of the thorax and larynx, producing deeper vocal tones, masculine strength, symmetry, and physiognomy, and greater courage and other mental endowments. Such changes do not occur when the testis are undeveloped or abstracted, as in eunuchs. Procreative capacity lasts till beyond 60, or in many recorded cases much longer.

THE FEMALE GENERATIVE ORGANS

Are the ovary, Fallopian tube, uterus, and external organs.

The Ovary is an oval gland, tied by a fold of peritoneum and an impervious ligament to the uterus. It consists of a fibrous coat, the tunica albuginea, like that of the testis, and a fibro-vascular stroma, in which are imbedded the Graafian vesicles, varying in number from 10 to 50, and in size from that

of a pin's head to that

of a pea.

Each ve

sicle or ovi-sac con- The Ovum, Zona, Pellucida, and Cells of the

sists of a cell wall,

Germinal Disc.

termed the membrana granulosa. The ovum is fixed in this epithelium by retinacula, according to Barry, and the rest of the vesicle in filled with fluid.

The Ovum is a circular body about in diameter, covered by a clear coat exactly similar to the elastic layers of the cornea, and termed the zona pellucida or yolk membrane. This encloses the yolk, a semi-fluid mass of granules and oil particles, and near its circumference the germinal vesicle of Purkinje, within which is lastly to be perceived the germinal spot. The yolk granules and ovum of the rabbit during rut are figured on the foregoing page.

The Fallopian Tube, or oviduct, begins by a fimbriated extremity, at which the peritoneal sac is open during conception, and terminates at the upper angle of the uterus. It has a strong fibro-muscular coat and a ciliated mucous surface, the movements of which are towards the uterus.

The Uterus is of a flattened pear shape, consisting of a fundus, at the angles of which the Fallopian tubes enter, a body and a cervix projecting into the vagina, and across which there is a slit-like opening-the os uteri. The cavity of the womb is very narrow and contains but a little mucus. Its wall is about an inch thick, and consists of muscle-cells and fibres running in every direction irregularly-save round the os, where they make a partial sphincter. Within the cervix are the glandulæ Nabothi, which secrete a plug of viscid mucus. The uterine nerves are derived from the sacral and hypogastric plexuses, and from many ganglia, according to Lee, in the impregnated organ. The uterus is said to have increased 24 times in size at the end of pregnancy. Its arteries, after this state had terminated, but before they had undergone much reduction, are here represented. The external organs are described in the anatomical treatises of Harrison, Ledwich, Gray, &c.

Menstruation is the occurrence which usually marks

the aptitude for impregnation-but a few cases are recorded where females became pregnant although the catamenia never appeared. Between the 14th and 16th

The Vessels of the Uterus six days after delivery.

year is the usual period for their commencement in this country; but in hot climates, and in girls of luxurious, idle habits, they have appeared much earlier. Greater obesity, enlargement of the mammæ and genitals, and the development of sexual passion mark the period. Menstruation occupies about 4 days, returns every month, and ceases with procreative power about the 50th year, when what is termed the "change of life" occurs. Menstrual blood, if obtained from the uterus, differs but little from

ordinary blood; but if mixed with the vaginal fluids, is acid, dark coloured, and fluid. About 6 ounces are poured out, but no fibrin is usually present.

The analogy of menstruation with "heat" in animals has been completely demonstrated of late years; but Cruikshank, in 1797, ascertained that an ovum was discharged with the menstrual fluid. Shortly after the oc

currence, sexual desires are increased, and impregnation is much more apt to occur. The catamenia cease during pregnancy and lactation, and occur at very irregular periods in many females who are sterile. Each discharge of an ovum leaves a cicatrix upon the ovary, which is termed the "false corpus luteum," that which is known as "true" occurring in pregnancy. They are thus contrasted by Dalton:

At the end of

three weeks, One month,

Two months,

Three-quarters of an inch in diameter; central clot reddish; convoluted wall pale.

Smaller; convoluted wall | Larger; convoluted wall

bright yellow; clot
still reddish.
Reduced to the condition
of an insignificant ci-
catrix.

bright yellow; clot still reddish. Seven-eighths of an inch in diameter; convoluted wall bright yellow; clot perfectly decolorized.

Still as large; clot fibri

nous; convoluted wall paler.

One-half an inch in dia

meter; central clot converted into a ra

diating cicatrix; wall without yellow colour.

The existence, however, of hematoidin crystals, or of fatty matter to which the yellow colour is due, affords evidence of the corpora lutea for a much longer period.