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Show 990 MESSRS. LISTER AND FLETCHER ON THE [Dec. 13, exhibits a rather peculiar structure. The thin median septum-the remains of the coalesced inner walls of the primitively distinct canals -remains more perfect than usual; and at a point rather behind the middle of the median chamber the septum leaves the middle line and becomes joined to the right side, thus forming a right cul-de-sac. The left part of the chamber, however, is continued onward, becomes more spacious where the right-hand one has ceased, and opens by a distinct orifice in the usual position. The lateral canals are long, and show the constriction distinctly. The cross fold, though not prominent, is visible. It may be remarked that when the lateral canals were opened they were found to be filled with a yellowish custard-like substance, in which lay several fibrous irregular structures. Similar hard bodies were found in the lateral canals of a specimen (2740 B ) in the Museum of the Royal College of Surgeons. Microscopic examination showed no trace of spermatozoa. The specimen B had a young one (measuring 8| in. from the snout to the root of the tail) in its pouch. The young was also a female. The condition of the vaginal canals of the mother was just as in specimen a, except that the median septum was less distinct, and the lateral canals were empty. The minute generative organs of the young (c) (which of course had not bred) were dissected ; and the median canal was found to end in two csecal pouches separated from the urogenital chamber by a thin partition. Externally there is no indication whatever of separation between the end of the median chamber and the urogenital canal. The specimen of Dendrolagus inusius was obtained young by the Society, and had lived alone in the Gardens for nearly three years. In all probability, then, it had not born young. In this animal (fig. 3) the lateral vaginal canals are so closely applied to the median canal that dissection is required to separate them. They exhibit the constriction and cross fold very distinctly. The median canal has a well-marked median fold along its ventral wall; and delicate trabeculae traversing the chamber complete the septum here and there. Posteriorly the canal terminates blindly in two lateral caeca, which are bounded by a thin wall at the sides, where they abut against the part where the lateral canals open into the urogenital chamber. The middle line is occupied by a short partition formed by the coalesced inner walls of the converging lateral canals, see p. 989. The specimen of Hypsiprymnus gaimardi had undoubtedly born young. The uteri open on prominences into the anterior end of the median vaginal canal; but the orifices are situated near one another on the dorsal wall, not at the sides as in other forms. The anterior part of the median septum is complete, and separates the two openings. The median canal is long and narrow, and passes down with a median ridge, but no further septum, and ends in two lateral culs-de- sac, one on either side of the middle line ; but there is no opening |