table sinuses, and projects beyond the proper erectile tissue of the glans. Besides the usual muscles of the penis there is, in Plantigrades, a pair arising from the sacrum diverging to include the sphincter ani, and then continued on to the dorsum penis as far as the bone. In the Otter the sperm-ducts have glandular terminations. Between the two there is a small body or canal which enters the urethra at the caput gallinaginis, but not with the vasa deferentia:' in this remnant of the protometra the cornua are filamentary, as in Meles. In Mustela martes, also, Hunter observes: There is a small cavity between the two vasa deferentia, at their entrance into the urethra, which will admit the small end of a small blow-pipe; but I could not find any natural opening into the urethra.' 2 In the Dog-tribe the scrotum is more prominent than in Mustelines or Plantigrades. The prostates form a protuberant body, and exude the secretion by several pores at the sides of the verumontanum. The spongy tissue of the urethra expands suddenly and considerably at the base of the glans, which has an ossicle: the blood is thence returned by two venæ dorsales penis': these are compressed by the action of 'levatores,' arising from the first caudal vertebra, passing one on each side of the anal sphincter, then converging to gain the dorsum penis, crossing the veins, and terminating at the base of the bulbous part of the glans. As long as the levatores' retain the stimulus to contract, after coition, the distended glans forms a mechanical impediment to retraction of the penis from the vagina.3 The ossicle is grooved for the urethra. The prostates are moderately large and lobulate in the Ichneumons, in which Cowperian glands also exist. In the Suricate (Rhyzana tetradactyla) the scrotum is as little marked as in Mustelines there are neither vesicular nor prostatic glands; but there is a pair of very large Cowperian glands, with the usual muscular capsule, and with unusually long ducts, through which the secretion is propelled to a dilatation near the distal end of the urethra: behind their orifices a semilunar fold opposes the retrograde passage of the secretion into the long tract of urethra intervening between it and the neck of the bladder. In the Zibet (Viverra Zibetha) there is a small prostate: beyond ib. p. 74. See also CCXLI". p. 49. I laid bare the penis of a dog, almost through its whole length; traced the two veins that came from the glans and separated them from the arteries by dissection, that I might be able to compress them without affecting the arteries. I then compressed the two veins, and found the glans and large bulb became full and extended.' XCIV. p. 32. which the muscular tract of the urethra extends far before its combination with the erectile parts of the penis: here, behind the bulb, is a pair of large Cowperian glands. The penis is continued from the junction of the crura, forward, in front of the pubis to a small prepuce at the fore part of the enlargement caused by the scent-glands. The glans penis is pointed and pre bent downward: it has no bone. This is wanting also in the Musangs, in which the prostate is large, but surpassed by Cowper's glands: the putial scent-follicles open upon a tract distinct from the anal glands. In the Hyæna the prostates fig. 528, c, c, are large and reniform, partially confluent behind: there is a minute flash-shaped protometra, ib. a, in the usual position between the ends of the sperm-ducts, b, b: these are less dilated and glandular than in most d 528 nat. size. CCXXXIX". Carnivores. The Cow- Accessory male glands and protometra of Hyena Striata, half perian glands, d, d, are elongate and pyriform: their ducts open far forward, nearer the glans penis than the vesical orifice. There is no ossicle: the penis is easily pulled out of the prepuce, and the prepuce then seems to be continued all along the penis to the end, and much of the same colour. This is not the same as in a dog," in which the covering of the glans is more distinct in texture and attachment. In the Cat the glans penis is beset with callous retroverted papillæ they are less numerous and conspicuous in the Tiger and Lion. In all Felines there is a small prostate, limited to the back part of the neck of the bladder: the muscular part of the urethra is long. Cowper's glands are large, and derive their muscular covering from a modification of the acceleratores,' of which an external may be distinguished from an internal portion. The erectores' arise each by a broad tendon from the pubis: anterior to this the compressores venæ dorsalis' take their origin, 1 CCXXXIV. vol. ii. p. 58. 6 · and converge to unite, at the symphysis pubis, in a strong common tendon, which passes over the vena dorsalis penis.' Two slender fasciculi derived from the 'retractor ani' pass along the bulb and under side of the urethra to the line of reflection of the prepuce, where they are lost in the skin of the glans: they bend back that part, in the unerect state, and cause the felines to be retromingent.' § 380. In Quadrumana.-The testes of the Aye-aye (Chiromys) occupy a sessile scrotum: the tunica vaginalis communicates with the peritoneal cavity, but by too contracted a canal to permit any return there of the testes, offering a notable difference from Rodents. There are no vesicular glands; but a moderate sized compact prostate, and a pair of flattened oval Cowperian glands, the ducts of which penetrate the urethral bulb. Besides the ' erectores' and 'acceleratores,' there is a pair of strong levatores penis' arising from a fascia below the symphysis pubis, crossing the vena dorsalis, and inserted by a common tendon into an ' ossiculum penis.' The penis, of a subconical form, projects about an inch, in the unerect state, it is covered by the thin naked skin of the prepuce, which has a transverse orifice. In the Slow Lemurs (Stenops Tarsius, Otolicnus, Perodicticus) there are vesicular glands in the form of oval subcompressed bags, with a plicate or honeycombed inner surface: their ducts terminate distinctly from those of the testes. The prostate has a bifid base and compact structure. The Cowperian glands are relatively large. The short penis has an ossicle, and projects, or hangs conspicuously as in Chiromys: the ossicle ends in a terminal process of the glans.' In the Makis (Lemur) the vesicular glands consist each of an elongate cæcal tube, bent inward and downward at their free end, with thin walls and a minutely rugous inner surface: in other respects the male organs resemble those of Chiromys. Each 'levator penis' arises from the upper part of the crus: they converge above the two venæ dorsales' to a common tendon which runs along the dorsum penis to the ossicle. The glans is large and expands to a free truncate end with the urethra opening near the centre of the disc; the sides of the glans are beset with small callous papillæ. The scrotum is more pendent in Platyrhine and higher Quadrumana: the vesicular glands have thicker parietes and a more lobulated or ramified form: the prostate is more compact: the Cowperian glands become reduced in size. The penis is prominent or pendulous in all. The glans terminates by a large expansion in Ateles. In Cebus capucinus Cuvier found no 1 xx. vol. iv. P. 101. 6 529 median septum dividing the corpus cavernosum: it is present in Accessory glands and protometra, Macacus Cynomolgus. § 381. In Bimana.-Here the testes pass, two or three months before birth, into a pendulous scrotum; the serous canal of communication becomes obliterated, and the tunica vaginalis is an independent short serous sac. All the accessory glands are well developed and differentiated, but of moderate proportions. 300 diam. The penis is pendulous and without a bone: Spermatozoa of Man, magn. the prepuce has a 'frænum.' The spermatozoa, fig. 530, have an ovoid or almond-shaped body, subcompressed, viewed sideways, with a filamentary vibratile appendage, averag to ing from of an inch in length. They are conveyed, with the fluid in which they move, by the spermducts to the beginning of the urethra. The ducts are slightly enlarged, chiefly 531 A posterior view of the human bladder and prostate: the spermiducts and vesiculæ are reflected downward; half natural size. XXVIII. through thickening of their walls, near their termination, fig. 531, f, as they pass along the inner sides of the vesicular glands, v; they again contract to communicate, each with the duct of the gland of its own side, at d. The vesicular gland is a fusiform multilocular bag about two inches in length and three quarters of an inch in greatest. breadth. The lower attenuated end penetrates the prostate between the lateral, p, and medial, c, lobes, and after joining the vas deferens, the common duct terminates at the side of the urethral depression called sinus pocularis,' fig. 532, g,g. Each ' vesicula' is invested by a fascia, on removal of which, with some maceration and dissection, it is shown to consist of a main tube with, commonly, three or four cæcal diverticular appendages. This tube has a much smaller calibre for a short distance from its junction with the vas deferens than elsewhere. The narrow portion is straight, and is commonly called the duct. The vesicular glands are found to contain a glairy mucus, deepening to a brownish colour soon after death, and containing stray spermatozoa. The prostate, figs. 531, 533, p, is a more compact glandular body surrounding the neck of the bladder and beginning of the urethra, deriving its name from its position in front of the vesicular glands. It is surrounded by a dense fascia, which adheres firmly to the glandular substance. This is of a lightish brown colour, and very firm texture. It forms two lateral lobes, of an ovoid shape, between which is a small middle lobe. It is composed of minute canals with blind follicular beginnings, which unite together to form ducts, opening in an oblique manner on the prostatic portion of the urethra. Their orifices are situated around the most elevated portion of the verumontanum, in the form of a crescent, fig. 532, e. The depression, or sinus,' in front of this valvular |