it is prolonged forward, to terminate in the prepuce, ib. f, e.

The testis, ib. g, is of a sub

compressed ovoid form, the

522

epididymis, h, l, rather closely attached to the testis and not longer than the gland. The vas deferens, m, enlarges at its terminal part, ib. 0, 0, and fig. 523, a, a, by the development of its inner tunic into numerous close-set transverse glandular lamellæ. The vesicular glands, fig. 522, x, x, fig. 523, b, b, are simple bladders with thin walls. In the transverse fold of peritoneum connecting together the enlarged parts of the sperm-ducts is situated the protometra, fig. 523, c, in form of a slender elongate tube, bifurcate, in the Zebra and Ass, at its blind end.1 The prostates are parenchymatous, and open into the upper or vesical end of the muscular tract of the urethra : at the lower end of this part are the Cowperian glands, fig. 522, y, y, which open into the bulb of the urethra.

The corpus cavernosum penis is formed by confluence of that of the two crura, into one body, without vertical septum, the parts composing its cells appear muscular to the eye, and in a Horse just killed they contract on being stimulated." The fibrous tissue here noticed lies between the vascular and sclerous parts of the cells. The glans has two lateral semilunar lobes, and at its apex a central pyramidal process on which the urethra opens. The 'crura penis' are surrounded by thick erectores,' having an extensive origin, fig. 524, d: two strong suspensory ligaments, ib. a, pass from the symphysis pubis to the dorsum. Besides the ordinary muscles, there is a pair of small levatores,' ib. b, c, serving mainly as compressors of the vena dorsalis penis, ib. e: there is xx. vol. iv. p. 93.

·

2

XCIV. p. 30.

6

also a pair of retractores' arising from the os coccygis, fig. 522, P, q, passing on each side the sphincter ani, r, then converging to run together along the urethral side of the penis, s, to the base of the prepuce. In the castrate horse these usually degenerate into elastic sclerous tissue.

§ 378. In Artiodactyla.-The male organs of the Suide are chiefly remarkable for the enormous development of the Cow

perian glands. The testes are perineal: the scrotum slightly projects; it is not pendulous. The vesicular glands are large, lobulated, with parenchymatous walls, their ducts terminate distinctly from those of the testes. The prostates are small, near the cervix of the vesiculæ. The muscular part of the urethra is of great length and the Cowperian glands are co-extended therewith each presents an elongate subtrihedral form, invested by a muscular capsule; the glandular parietes are very thick:

the terminal duct opens beyond a transverse valvular fold separating the bulbous from the muscular part of the urethral canal. The penis shows a sigmoid flexure, and has a pair of retractores,' arising from the hollow of the caudal end of the sacrum, and inserted at the end of

Suspensory ligaments and muscles of penis, Horse.

The Ruminant Artiodactyles are devoid of vesicular glands; their testes pass into a pedunculate scrotum. The spermatic arteries form, by their close and numerous convolutions, a plexiform mass, which is specially notable in the Bull. The vasa deferentia slightly enlarge at their termination in the Camel, but are not there different in structure from the rest of the sperm-ducts: they terminate upon a broad wrinkled verumontanum. The prostate is a transversely oblong compact body with a smooth exterior, the secretion passes by several orifices into the depressions at the sides of the verumontanum. Cowper's glands are of moderate size, subcircular, compact in structure, with a thick muscular capsule. The corpus spongiosum commences by a plexus of veins affecting a parallel course around the membranous part of the urethra, but convolute in diverse directions to form the bulbous expansion; advancing from which the veins become reduced to two or three in number, running parallel with each other and the urethra. The cavernous part of the penis forms a slender cylinder, it extends forward beneath the linea alba, closely connected therewith, making a ridge along that part of the abdominal surface; then becoming free and receiving a reflected covering of skin, or prepuce,' anterior to which usually depends a tuft of hair. The glans, in the Camel, is long, pointed, with its apex continued beyond the urethral opening and bent back. In the Goat, fig. 525, the dilated terminal parts of the spermducts, a, a, have a glandular thickening of the inner tunic.

The

prostates, b, b, have each a small central cavity; whence the duct is continued to terminate near the sperm-duct, in an oblong depression by the side of the verumontanum: on a small fold of

525

b

Testes, prostates and protometra, Goat. ccxXXIX”.

this part is the orifice of the protometra which is continued, at

a

526

e, between the dilated sperm-ducts, closely attached thereto by areolar tissue; then dividing into two horns diverging and closely apposed to the sperm-ducts, a, a, as far as the epididymis, in which they are lost. The Cowperian glands, two on each side, open upon the margin of a fold at the bulb of the urethra. The prostatic glands in the Deer, fig. 526, b, b, are more slender in proportion to their length than in the Goat. The protometra, c, is reduced to a hardly distinguishable trace; and its cavity, which exists in the embryo, is obliterated at birth.

In the Bull the narrow elongate prostates are irregularly contorted. The erectores and acceleratores' are powerful muscles. The slender 'retractores' arise from the anterior commissure of the sphincter ani. Prostates and protometra, Deer. There are preputial follicles in most Ruminants, especially the Antelopes; but only in the Muskdeer do they attain the size and structure described in the preceding chapter. In no hoofed Mammal is there an 'os penis.' § 379. In Carnivora. The outward indications of the male sex

are hardly distinguishable in the Seal tribe. Here, the testes, when extra-abdominal, make no scrotal projection: they are imbedded in areolar tissue, between the pubis and the thighs: the tunica vaginalis communicates freely with the abdomen: the sperm-ducts take the usual course. There are no vesicular glands; there is but a small subbilobed prostate. The penis makes no outward projection: the preputial opening, about six inches in advance of the vent, is inconspicuous. The glans penis is pointed, supported by a bone about half an inch long, in Phoca vitulina, into which are inserted a pair of 'retractores,' arising from the anterior commissure of the anal sphincter. The remnant of the protometra in Ph. vitulina, is but two lines in length; the orifice behind the verumontanum is rarely patent. The os penis of the Walrus is a massive subcylindrical bone, sometimes two feet in length, expanded at one end, where the cancellous structure prevails.1

The testes lie under the skin of the groin in otters, under that of the perinæum in civets. The scrotum, where best developed in Carnivora, is hairy and less pendulous than in Ruminants. As in these, the vesicular glands are absent 2; the prostatic glands are small and compact. The penis, save in Canidæ, Viverridæ, and Hyana, has a bone.

527

In the Bear the sperm-ducts are enlarged and in close contact at their terminations, with thick follicular walls beyond this glandular part they retain their width, but contract to open upon the verumontanum.3 A thin layer of prostatic substance surrounds the beginning of the urethra. The os penis in Ursus arctos may be 6 inches in length. In the Subursine genus Meles a remnant of the protometra, fig. 527, a, rises between the glandular ends of the sperm-ducts, b, b: its cornua are reduced to mere filaments, c: the prostate is better in Ursines, especially in the Racoon, in which it is in advance of the neck of the bladder. In the Kinkajou the os penis is sub-bifurcate at the distal end, which is covered, as in most Subursines and Mustelines, by the membranes of large dila

1 XLIV. p. 638, No. 3919.

Protometra, a, nat. size,
Badger. CCXXXIX".

developed than

2 Les vésicules séminales existent dans les coatis,' XII. tom. viii. p. 160. Hunter, however, expressly affirms of his Swash,' which I determined by the skull (No. 4669, XLIV.) to be a young Coatimondi, that it has no vesiculæ seminales.' ccxxxvI. vol. ii. p. 90. The same result has been had from subsequent dissections at the Zoological Gardens. CCLXXIII".

3

CCXXXVI. vol. ii. p. 92, note 3.

A fossil specimen of this bone, in Ursus spelæus, measured nine inches.