Cowperian Glands opening into it, together with the Rectum and Anopreputial Glands of Rabbit (Lepus cuniculus) seen from behind.

One-third larger than the parts figured are in the period of sexual activity of an adult male.

a. Urinary bladder. The upper half has been removed and the cavity laid open, and the walls reflected so as to show the openings of the two ureters towards its lower end.

b. Uterus masculinus (in section), with prostatic glands on either side.

c. Rectum, with two of the cystic stages (Cysticercus pisiformis) of Taenia serrata attached to the external surface of the longitudinal muscular coat of the intestine, which has been reflected to show their connection with it.

d. Urogenital canal. A wire passes along it to its termination at the external orifice of the penis, having been introduced into it from the bladder at a. The penial urethra conveys both urinary and seminal products in all mammals above the Monotremata, in which group it conveys seminal products only, reversing the functions of the homologous canal of those female mammals, such as the Rat and the Mole, in which there is a closed clitorid urethra. e. Anus.

f. Penis, with vertically elongated backward-looking orifice.

g. Hairless patch on to which the ano-preputial glands open. h. Upper prostatic glands.

i. Lower prostatic glands. j. Cowper's glands.

k. Larger and smaller ano-preputial glands, rudimentary in man.

l. Corpus cavernosum of right side in section, with parts of the pubo-cavernosus and ischio-cavernosus muscles lying upon it.

A comparison of this preparation with such figures as those of the homologous organs in the human subject at pp. 419, 428, figs. 304, 310 of Quain's Elements of Anatomy, 8th ed. 1878, will show clearly the different proportions of the organs in the two subjects respectively, whilst a comparison of it with the similarly dissected and displayed preparation of the female organs of the Rabbit (see infra, Prep. 9, Fig. 5, p. 37, and Description, pp. 34-38) will show the close correspondence which exists between the male and female organs in this animal from the commencement of the urogenital canal outwards. The structure of the crura clitoridis and that of the crura penis are strikingly similar, especially in the very considerable thickness of their external fibrous sheath. The median septum which these sheaths form by their apposition remains distinct throughout the length of the compound organ they make up, as is the case in many mammals of the Rodent and other orders which possess a penial ossicle, whilst in the Ungulata, such as Cervus, Sus, Tapirus, Equus, and the Cetacea there is neither median septum nor penial ossicle.

An excellent article on the male generative apparatus and the anal glands of Mammals by Prof. Leydig is to be found in the Z. W. Z. ii. pp. 1-58, 1850. One of similar merit on the Uterus masculinus, s. Vesicula prostatica, by Professor R. Leuckart, is contained in the Cyclopaedia of Anatomy and Physiology, sub voc. 'Vesicula prostatica,' 1852. See also E. H. Weber, Abhandlungen Jablonowskischen Gesellschaft, 1846, pp. 382-385, 396, 405, Taf. v. figg. 1-3, where the generative organs of the Rabbit are figured; as also one by Van Deen, Z. W. Z. i. Taf. xx. 1849, and the work by Martin-Saint-Ange, LAppareil reproducteur des Animaux Vertdbre's, Pl. i. and ii. 1854. See also Huschke in Soemmering's Anatomie, 1844, and a good article, translated by Prof. Peters, in Muller's Archiv, 1849, from the Swedish of F. Wahlgren. A uterus masculinus of somewhat similar proportions is figured by Pallas, 'Novae species Glirium,' 1778, from the Arctomys bobac, p. 117, Taf. ix. fig. 5, but in the genus Lagomys, judging from his figures 9 and 15, Taf. iv. B, we must suppose the two vasa deferentia to be, by a very unusual arrangement, fused into a single tube but a very short distance above the bulb of the urethra, and the uterus masculinus to be absent contrary to what Leuckart has (l.c. p. 1419) suggested.

The organ is said to be somewhat smaller in the Hare than in the Rabbit. It is much smaller relatively in the human subject than in most Mammalia in which it has been seen; for figures, however, of a large specimen from a human embryo of 32 weeks, see Betz in Muller's Archiv, 1850, Taf. ii.

For the General Morphology of the male and female generative organs in Mammals, see Allen Thomson in Quaint Elements of Anatomy, vol. ii. 1882, p. 911, and Banks 'On the Wolffian Bodies,' 1864, ibi citat; Leuckart, Zur Morphologie und Anatomie der Geschlechtorgane, aus Gottingen Studien, 1847, and l. c. supra; Meckel, Zur 'Morphologie der Harn- und Geschlechtswerkzeuge, 1848; Fredrik Wahlgren in Muller's Archiv, 1849, pp. 686-713; Rathke, Vortrage zur Vergleichenden Anatomie, 1862, pp. 135-170; Gegenbaur, Grundriss der Vergleichenden Anatomie, 1878, p. 645, where the uterus masculinus is taken as the homologue rather of the vagina than of the uterus. See also Watson, P. Z. S. 1878, p. 424; Young, Journal of Anat. and Physiol. 1879, p. 315; and for opening of vasa deferentia into uterus masculinus, see same two authors, on Elk, J. L. S. 1878, p. 375; on Hyaena crocuta, P. Z. S. I.c.; and Dr. Young on Koala, l. e.

For Taenia serrata and Cysticercus pisiformis, see Preps. 46 and 47 post. For figures, see P. J. van Beneden, Memoire sur les Vers Intestinaux, Paris, 1858, p. 148, Pl. xx. And for the fact that this particular parasite affects the locality h as a 'point de predilection' (much, perhaps, in the way that the stress of certain infectious diseases has preferential sites), see Martin St. Ange, l. c. p. 7.

For the migration of these and other Cysticerci from their first site in the liver, and for the recovery of the liver from the injury thus inflicted, see Leuckart, Die menschlichen Parasiten, 1879, pp. 92, 93, and 174. Flukes will similarly migrate from the liver into the peritoneal cavity.