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Show 1881.] VAGINAL APPARATUS IN THIS MACROPODID.E. 987 into the cavity of the canal just beyond the constriction, which arranged as to form a valvular barrier to a body passing up the canal. W e have been unable to obtain any history of the second specimen of M. major, from the Museum at Cambridge. The median vaginal canal had been opened in order to display the interior. The remains of a median septum were visible, and, besides this, two low crescent-shaped folds of the lining menbrane, which extend with their concavity forward from the middle line of the ventral wall to the sides. The median canal when traced back becomes much narrowed ; it can, however, be followed to a point where it abuts against the left lateral canal just as this opens into the urogenital chamber-at a point, that is, just to the left of the middle line. Although our specimen thus agrees with those of other observers, in the fact that the median chamber is a cul-de-sac, it differs from them in the fact that the walls are continuous by means of their proper tissue with those of the lateral and urogenital canals. Halmaturus Bennetti exhibits the open condition of the median canal. There were well-marked muscular thickenings in the lateral canals, but no valvular folds. Halmaturus derBianus (no history) was in a similar condition ; but the valvular fold was well marked. The specimen a of Halmaturus ualabatus was the first example in which our attention was drawn to the subject. It died in the Society's Gardens on June 30th. The measurement from the nose to the root of the tail was 16 inches-that is, 12 inches shorter than its mother. It was bred in the Gardens, and was taken on the list of the Society's collection on May 19th, i. e. at the time when it was old enough to leave the mother's pouch. The evidence that she had not born young appears to us conclusive. It will be observed that only 42 days had elapsed between the date of entry on the list and the date of death ; so, if young had been produced, it must have been during that period. The period of gestation which Prof. Owen gives for Macropus major is 39 days. Assuming a period of about the same length for II. ualabatus, we must suppose that, if young had been produced, it was born towards the end of those 42 days, so that lactation would be at its height at the time of death. Now it was observed at the time (1) that there were no young in the pouch, and (2) that the teats were so small as not at first to be recognized; for we find from the notes taken at the time that it was not till after a second more careful examination that the four minute teats were seen, arranged in a crescentic line on the body-wall of the pouch. W e may take it for certain, then, that the specimen examined had not born young. The arrangement found was as follows (see fig. 2, p. 988):-The median vaginal canal was wide in front and gradually contracted posteriorly, where it passed by a distinct opening into the urogenital chamber just above the opening of the urethra. The lateral canals |