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Show 1878.] GENERATIVE ORGANS OF HYAENA CROCUTA. 421 single mass surrounding the canal of the urethra. Further, in the female the corpora spongiosa take no part in the formation of the glans clitoridis, whilst in the male the glans penis is formed by the spongy body. The penis, formed as just described, measures 8 inches in length from the bulb of the urethra to the apex of the glans. Muscles of Penis.-Of these there are three which are bilateral, and one which is common to both sides. (1) The ischio-cavernosus or erector penis is very strong, and arises from the ischium immediately iu front of the tuberosity. The fibres pass forward and are inserted into the corresponding corpus cavernosum close to the junction of the latter with its fellow on the opposite side. The muscle covers the crus penis. (2) The bulbo-cavernosus is also strong, and arises from a median tendinous band which separates it from its fellow. The fibres pass transversely outward so as to cover the bulb of the urethra, and are inserted into the corpus cavernosum along the inner border of the preceding muscle. (3) Betractor penis. In m y paper on the female organs of H. crocuta I expressed my belief that the retractors of the clitoris probably arise from either the ischium or pubis. I am now satisfied from m y examination of those of the male that such is not the case, hut that in both sexes they arise from the lower surface of the sacrum. In the male each retractor is a broad but thin muscle which, arising from the pelvic surface of that bone, passes backward and downward and reaches the side of the rectum. Some of the fibres terminate on the gut, where they lie under cover of the levator ani; but the greater number form a narrow riband-like muscle, which passes downwards and extends along the under-surface of the penis in contact with its fellow to be inserted, as in the female, into the corpus cavernosum just behind the glans. (4.) Elevator urethree. The muscle so named is very strong, being nearly as thick as the erector. It is a flattened band, and arises from the inner surface of the ischium 1 inch in front of the tuberosity. The fibres pass downward and forward, and terminate below the angle formed by the junction of the membranous and spongy portions of the urethra on a tendon which is common to it and to the muscle of the opposite side. Lying, as it does in the normal position of the animal, below the urethra, this tendon when the muscular fibres contract will tend to elevate and at the same time to compress the urethral canal. A large artery, vein, and nerve derived from the pudics pass together along the outer side of each cavernous body as in the female, and terminate close to the glans. Another artery of large size, also derived from the pudic trunk, passes into the crus penis of each side, and apparently supplies the erectile tissue. Comparison of the Male Organs of allied Species.-Having now described the male organs of H. crocuta, it may be well to compare them with those of closely allied species. The number and arrangement of the anal glands is similar in both sexes of this species ; and therefore there is little to add to what I have already said regarding them in m y communication on the female organs. In m y descrip- |
