510

fig. 511, c, is considerable1: the globus major of the epididymis lies in the cremasteric pouch, which is inverted when the reduced testis returns into the abdomen. The vasa deferentia, ib. f, receive at their termination the secretion of the small glands with a granulated exterior, e: the vesicular glands,' ib. a, a, are large, lobulate, and exude a hardish cheese-like secretion. The prostatic glands, b, c, are masses of slender subconvolute tubes. The Cowperian glands, of the usual compact form, lie one on each side of the rectum and send their long ducts to the large foramen cæcum' at the urethral bulb. The penis has its levator' muscle and ossicle: the prepuce is served by a pair of glands secreting a whitish

6

mucus.

The spermatozoa of the Murida have the 'body' shaped like the bent blade of a knife, when viewed in profile, fig.

a

Male organs, Water-vole. CXXII'.

512, A, B; the vibratile 'tail' is very long: in the Squirrel (fig. 513) the body is lamelliform, with the surfaces subbiconcave, and the margin thickened an

teriorly the 'tail' is of moderate length. It is relatively shorter to the body in the Guinea-pig, fig. 514,d: in this figure a portion of a tubule of the testis is magnified 300 diameters, showing the basilemma a, a, its lining(precipitate) of nucleate corpuscles and granules, b: with the developed nuclei of detached cells, forming the spermatozoa, a.

511

A

Male organs, Rat.

C

$372. In Insectivora. The periodical enlargement and

As in birds; see vol. ii. p. 243, and xx. vol. iv p 79.

'descent' of the testes are better marked, perhaps, in some Insec

512

B

Spermatozoa, A, of the Rat: B, of the Mouse: magn. CCCVI.

513

tivora than in Rodentia. In December the testes of the Mole lie on each side of the urinary bladder, with the inverted cremasterie pouch attached to the great end of the epididy mis: in March they are protruded into serous sacs, which look like a continuation of the abdominal cavity beneath the base of the tail. The prostatic glands, which begin to increase in February, acquire an enormous size and conceal the urinary bladder towards the latter end of March. The Cowperian glands lie beneath the integument above the root of the tail, and send their duct to terminate in the urethral bulb. The penis, bent backward upon itself, terminates in a very long conical glans with an ossicle, lodged in a preputial sheath, which projects freely, a short distance below the anus. In a Cape-mole (Chryso chloris) I found the testes near the kidneys; but the convolute course of the vasa deferentia indicated their periodical movements. The accessory glands are better differentiated into vesicular and prostatic' than in Talpa.

In the Hedge-hog the vesicular glands, which become enormous at the rut, lie mainly behind the urinary bladder; the flattened mass of prostatic glands rises in front: they are supported by folds of peritoneum. The Cowperian glands, as in the Mole, are extra-pelvic, behind the ischia, and accordingly reach the urethral bulb by very long ducts. The penis is long and bent when at rest. There are two levatores' which rise from the ischial tuberosities behind the erectores:' passing along the sides of the penis, their tendons meet upon the 'dorsum' near the reflection of the long prepuce, crossing the vena dorsalis' and inserted into the ' ossiculum glandis': the urethra opens upon a special process which projects beyond the main body of the glans. In the Shrews, temporary receptacles in the perinæum receive the enlarged testes during the rut; but do not project, as a scrotum. The epididymis

Spermatozoa, Squirrel: magu. CCCVI.

extends round two-thirds the circumference of the testis. The terminal half of the sperm-duct is dilated, like a uterine horn.

In a proboscis-shrew (Rhynchocyon) the testes, fig. 515, t, have a long epididymis, e, terminating in the usual convoluted vas

6

6

deferens, d: large conglomerate vesicular and prostatic glands, p, p, extend along the upper half of the elongate muscular part of the urethra: a pair of small Cowperian glands, e, e, open into the bulbous part: this is grasped by a strong accelerator,' b, b. Above the crura corporis cavernosi' are the 'levatores penis,' k, k. The glans is nearly half the length of the penis; its termination is suddenly attenuated, with a crenate border and a filamentary appendage: there is no ossicle in this or other shrews.

P

In the Bats the prepuce is relatively longer in its freely projecting part than in Moles and Shrews, and the penis is pendulous. The glans offers odd modifications in some species: a lateral pair of prominences extend its upper surface in Vespertilio scrotinus, the lower surface being carinate and produced into a hirsute point upon which the urethra opens. In Galeopithecus the glans shows two lateral longi-. tudinal prominences which do not extend to the pointed urethral termination. There is an ossiculum penis in Pteropus: these furgivorous bats have large vesicular glands. § 373. In Bruta.-A long epididymis characterises the testicle

Male organs, Rhynchocyon. LXXXIV'

in the Armadillo: the tubuli testis are relatively large and disposed in narrow oblique folds beneath the tunica albuginea. The testes lie above the brim of the pelvis: they appear not to pass out of the abdomen, for the vasa deferentia are short and unconvolute these, converging behind the bladder, penetrate a compact triangular prostate (or protometra?): there are no vesicular glands. The Cowperian glands are situated behind the urethral bulb: each has its muscular capsule. Two levatores' arise from the symphysis pubis and send a common tendon to the glans penis. The preputial sheath is of great extent, and the reflected membrane is coloured by a dark pigment. The penis has a disproportionate length, in relation to the mechanical obstacles to coition presented by the body-armour. The testes are constantly abdominal in the Anteaters and Sloths. Hunter notes that the ducts of the vesicular glands of the Anteater open into the urethra by a separate sulcus from the common canal.'' There are no vesicular or prostatic glands in the Sloth. The penis is a short flat body inclosed in a prepuce which is within the verge of the anus. It is not above two-tenths of an inch in

length, and terminates in an obtuse point. It has a groove which runs along its under surface, and which makes the point somewhat forked.'"

$374. In Cetacea.-Here the testes are abdominal, situated at the hinder part of the cavity between the great depressor muscle of the tail and the transversalis abdominis: they greatly augment in size at the rut, but do not change in position: in their quiescent state they assume an elongate form, fig. 516, a, and the epididymis, b, extends unusually far in advance of the gland itself. The vas deferens, c, has a short tract, but is convolute. There are no vesicular glands. The prostatic part of the urethra, ib. k, k, is surrounded by a thick capsule of muscular fibres. The protometra is reduced to a small, elongate cæcum, fig. 517, a,

concealed in the prostate, and opening by the usual transverse crescentic slit, ib. c, into the urethra, between and a little beyond the terminal orifices, ib. b, b, of the sperm-ducts.

6

517

The penis commences by two cavernous crura inclosed in strong erectores,' arising each from the loosely suspended ischial ossicle of the same side. The crura coalesce into a single cavernous body surrounded by a very thick sclerous sheath. After the junction of the crura the penis, in Delphinidæ, describes a close sigmoid curvature, before terminating in the long, straight, gradually tapering glans. The corpus spongiosum commences by a bulbous expansion, fig. 518, 1, embraced by the accelerator fibres,' g; but degenerates into little more than a close venous plexus as it penetrates, in the Porpoise, the corpus cavernosum; it then emerges and extends along the under part of the corpus cavernosum, to re-expand into the venous plexus surrounding the tuberous basis of the glans. The upper part, or dorsum, of the cavernous body

is grooved for the lodgment of the plexiform vena dorsalis. In the unexcited state the penis is withdrawn and concealed in the long prepuce, the orifice of which is considerably in advance of the vent. The retraction is effected by a pair of muscles, m, arising from the aponeurotic commissure anterior to the sphincter ani e, and rurning along the under or urethral side of the penis to be inserted into the sclerous basis of the glans. The protrusion of the organ is aided by the transverse fibres of the 'panniculus carnosus' surrounding the preputial sheath. The section of the penis of a Balanoptera preserved by

518

Male organs, Phocæna. XII.

Hunter shows a single corpus cavernosum grooved above for the