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tened prolongations, which constitute incomplete septa or partitions. These form triangular spaces, filled with seminiferous vessels, that pass, with considerable regularity, towards the superior margin and the corpus highmorianum.

These elements united constitute the testicle, the substance of which is soft, of a yellowish-gray colour, and divided by prolongations of the tunica albuginea, into a considerable number of lobes and lobules. It seems to be formed of an immensity of very delicate, tortuous filaments, interlaced and convoluted in all directions, loosely united, and between which are ramifications of the spermatic arteries and veins.

According to Monro Secundus, the seminiferous tubes of the testicle do not exceed the th part of an inch in diameter, and, when filled with mercury, the 6th part of an inch. He calculated, that the testis consists of 62,500 tubes, supposing each to be one inch long; and that if the tubes were united, they would be 5208 feet and 4 inches long. The tubuli seminiferi finally terminate in straight tubes, called vasa recta, which unite near the centre of the testis, in a complicated arrangement bearing the name rete testis or rete vasculosum testis; from this from 12 to 18 ducts proceed upwards and backwards to penetrate the corpus highmorianum and the tunica albuginea. These ducts are called vasa efferentia. Each of them is afterwards convoluted upon itself, so as to form a conical body, called conus vasculosus, having its base backwards; and at its base the tube of each cone enters the tube of which the epididymis is formed.

The epididymis is the prismatic arch, B, C. Fig. 127, which rests

Fig. 127.

vertically on the back of the testicle and adheres to it by the reflection of the tunica vaginalis, so as to appear a distinct part from the body of the testis. It is enlarged at both ends; the- upper enlargement being formed by the coni vasculosi, and called the globus major; the lower the globus minor. The epididymis is formed by a single convoluted tube, the fourth of a C lineindiameter. When

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Left hand Fig. The testicle covered by its membranes, and seeming the tube attains the like one body.-Right hand Fig. The testicle freed from its outer coat.

-A. Body of the testicle.-B. Commencement of the epididymis, or lower end 0f the gloglobus major.-C. The small head or globus minor.-D. The vas de- bus minor, it becomes

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less convoluted, enlarges, turns upwards, and obtains the name of vas deferens.

The testes of most animals, that procreate but once a year, are comparatively small during the months when they are not excited. In man, the organ before birth, or rather during the greater part of gestation, is an abdominal viscus; but, about the seventh month of foetal existence, it gradually descends through the abdominal ring into the scrotum, which it reaches in the eighth month, by a mechanism to be described hereafter. In some cases, it never descends, but remains in the cavity of the abdomen, giving rise to considerable mental distress in many instances, and exciting the idea that there may be a total absence of the organs, or that, if they exist, they cannot effect the work of reproduction. The uneasiness is needless, the descent appearing to be by no means essential. It has been sufficiently demonstrated, that individuals, so circumstanced, are capable of procreation. In many animals, the testicles are always internal; whilst, in some, they appear only in the scrotum during the season of amorous excitement. Foderé has indeed asserted, that the crypsorchides, or those whose testes have not descended, are occasionally remarked for the possession of unusual prolific powers and sexual vigour.⁕

It appears, that there is a set of barbarians at the back of the Cape of Good Hope, who are generally possessed of but one testicle, or are monorchides; and Linnæus, under the belief that this is a natural defect, has made them a distinct variety of the human species. Mr. Barrow has noticed the same singularity; but Dr. Good thinks it doubtful, whether, like the want of beard amongst the American savages, the destitution may not be owing to a barbarous custom of extirpation in early life. The deviation is not, however, more singular than the unusual formation of the nates and of the genital organs of the female in certain people of these regions, to which we shall have to refer.

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The testicle is connected with the abdominal ring by means of the spermatic cord, a fasciculus of about half an inch in diameter, which can be readily felt through the skin of the scrotum. It is formed, essentially, of the vessels and nerves that pass to or from the testicle; the spermatic artery, spermatic veins, lymphatics and nerves of the organ, and the vas deferens, or excretory duct. These are bound together by means of cellular tissue; and, externally, a membranous sheath of a fibrous character envelopes the cord, and keeps it distinct from the surrounding parts, and especially from the scrotum. When the cord has passed through the abdominal ring, its various elements are no longer held together, but each passes to its particular destination.

"Ces organes paraissant tirer du bain chaud où ils se trouvent plongés plus d'aptitude à la sécrétion que lorsqu'ils sont descendus au dehors dans leurs enveloppes ordinaires"!—Traité de Médecine légale, t. 1, p. 370.

The scrotum or purse is a continuation of the skin, of the Inner side of the thighs, the perineum, and the penis. It is symmetrical, the two halves being separated by a median line or raphe. The skin is of a darker colour here than elsewhere; is rugous, studded with follicles, and sparingly furnished with hair. This may be considered its outermost coat. Beneath this is the dartos, -a reddish, cellular membrane, which forms a distinct sac for each testicle, and a septum—the septum scroti—between them.

Much discussion has taken place regarding the nature of this envelope; some supposing it to be muscular, others cellular. Breschet and Lobstein affirm, that it does not exist in the scrotum before the descent of the testes, and they consider it to be formed by the expansion of the gubernaculum testis. Meckel, however, suggests, that it constitutes the transition between the cellular and muscular tissues, and that there exists between it and other muscles the same relation that there is between the muscles of the superior and inferior animals. It consists of long fibres considerably matted together, and passing in every direction, but which are easily separable by distention with air or water, and by slight maceration.

The generality of anatomists conceive it to be of a cellular character, yet it is manifestly contractile, corrugates the scrotum, and probably consists of muscular tissue also. Dr. Horner, indeed, affirms that he dissected a subject in January, 1830, in which the fibres were evidently muscular, although interwoven.

Beneath the dartos a third coat exists, which is manifestly muscular:—it is called the cremaster or tunica erythroïdes. It arises from the lesser oblique muscle of the abdomen, passes through the abdominal ring, aids in the formation of the spermatic cord, and terminates insensibly on the inner surface of the scrotum. It draws the testicle upwards.

The cellular substance, that connects the dartos and cremaster with the tunica vaginalis, has been considered by some as an additional coat, and termed tunica vaginalis communis.

The tunica vaginalis or tunica elytroïdes is a true serous membrane, enveloping the testicle and lining the scrotum; having, consequently, a scrotal and a testicular portion. We shall see, hereafter, that it is a dependence of the peritoneum, pushed down by the testicle in its descent, and afterwards becoming separated from any direct communication with the abdomen.

The vas deferens or excretory duct of the testicle commences at the globus minor of the epididymis, (C, Fig. 127,) which is itself, we have seen, formed of a convoluted tube. This, when unfolded, according to Monro, measures as much as thirty-two feet. As soon as the vas deferens quits the testicle, it joins the spermatic cord, passes upwards to the abdominal ring, separates from the blood-vessels on entering the abdomen, and descends downwards and inwards to the posterior and inferior part of the bladder, pass

ing between the bas-fond of the latter and the ureter. It then converges towards its fellow along the under extremity of the bladder, at the inner margin of the vesicula seminalis of the same side, and ultimately opens into the urethra near the neck of the bladder. (Fig. 124.) At the base of the prostate it receives a canal from the vesicula, and continues its course to the urethra under the name of ejaculatory duct.

The vas deferens has two coats, the outermost of which is very firm and almost cartilaginous; but its structure is not manifest. The inner coat is thin, and belongs to the class of mucous membranes.

Fig. 128.

The vesiculæ seminales, E, Fig. 124, are considered to be two convoluted tubes,—one on each side,—which are two inches or two inches and a half long, and six or seven lines broad at the fundus, are situated on the lower fundus of the bladder, between it and the rectum and behind the prostate gland. At their anterior extremities they approach each other very closely, being separated only by the vasa deferentia. When inflated and dried, they present the appearance of cells; but are generally conceived to be tubes, which, being convoluted, are brought within the compass of the vesiculæ. When dissected and stretched out, they are four or five inches long by about one-fourth of an inch in diameter. Amussat, however, denies this arrangement of the vesiculæ; and he affirms, that he has disco- V. Section of vas deferens.-S. Section of vevered them to be formed of a mi- sicula seminalis.-E. Section of ejaculatory duet. nute canal of considerable length, variously convoluted, the folds of which are united to each other by cellular filaments, like those of the spermatic vessels.

At the anterior part, termed the neck, a short canal passes off, which unites at an acute angle with the vas deferens, to form the ductus ejaculatorius.

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The vesiculæ are formed of two membranes; the more external like that of the vas deferens, and capable of contracting in the act of ejaculation; and an internal lining, of a white, delicate character, a little like that which lines the interior of the gall-bladder, and supposed to be mucous. Although the vesiculæ are manifestly contractile, no muscular fibres have been detected in them. They are found filled, in the dead body, with an opaque, thick, yellowish fluid, very different, in appearance, from the sperm ejaculated during life.

The prostate gland, Fig. 124, D, is an organ of a very dense tissue, embracing the neck of the bladder, and penetrated by the

urethra, which traverses it much nearer its upper than its lower surface. The base is directed backwards, the point forwards, and its inferior surface rests upon the rectum, so that, by passing the finger into the rectum, enlargements of the organ may be detected.

The prostate was once universally esteemed glandular, and it is still so termed. It is, now, generally and correctly regarded, as an agglomeration of several small follicles, filled by a viscid, whitish fluid. These follicles have numerous minute excretory ducts, which open on each side of the caput gallinaginis.

The glands of Cowper are two small, oblong bodies; of the size of a pea; of a reddish colour, and of a somewhat firm tissue. They are situated anterior to the prostate, parallel to each other, and at the sides of the urethra. Each has an excretory duct, which creeps obliquely in the spongy tissue of the bulb, and opens before the verumontanum.

The male organ or penis consists of the corpus cavernosum and corpus spongiosum; parts essentially formed of an erectile tissue, and surrounded by a very firm elastic covering, which prevents over-distention, and gives form to the organ.

The corpora cavernosa constitute the great body of the penis. They are two tubes which are united and separated by an imperfect partition. Within them a kind of cellular tissue exists, into which blood is poured, so as to cause erection. The posterior extremities of these cavernous tubes are called crura penis. These separate in the perineum, each taking hold of a ramus of the pubis; and, at the other extremity, the cavernous bodies terminate in rounded points under the glans penis. The anatomical elements of the internal tissue of the corpora cavernosa, are,—the ramifications of the cavernous artery, which proceeds from the internal pudic; those of a vein bearing the same name; and, probably, nerves, although they have not been traced so far. All these elements are supported by filamentous prolongations from the outer dense envelope. A difference of opinion prevails amongst anatomists, with regard to the precise arrangement of these prolongations. Some consider them to form cells, or a kind of spongy structure, on the plates of which the ramifications of the cavernous artery and vein and of the nerves terminate, and into which the blood is extravasated.

Others conceive, that the internal arrangement consists of a plexus of minute arteries and veins, supported by the plates of the outer membrane, interlacing like the capillary vessels, but with this addition, that, in place of the minute veins becoming capillary in the plexus, they are of greater size, forming very extensible dilatations and net-works, and anastomosing freely with each other. If the cavernous artery be injected, the matter first fills the ramifications of the artery, then the venous plexus of the cavernous bodies, and it ultimately returns by the cavernous vein, having produced

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