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Show 97S MESSRS. LISTER AND FLETCHER ON THE [Dec. 13, an orifice large enough to admit a hog's bristle was to be met with, and that " immediately after parturition, the parts are nearly brought back into their original state ; the only circumstance deserving note is, that the opening leading directly from tbe uterus (that is the median vaginal canal) to the vagina (urogenital sinus), which is not met with in the virgin state, after being enlarged by the passage of the foetus, forms a projecting orifice and almost wholly conceals the meatus urinarius." Concerning the views of Cuvier and of Geoffroy St.-Hilaire we are not able to say much. From allusions in several of the papers shortly to be mentioned, it would appear that Cuvier was opposed to the view that a direct communication existed between the median vaginal and the urogenital chambers, while G. St.-Hilaire was in favour of such a view. Owing to the want of satisfactory references, we have been unable not only to meet with the original papers in which these two distinguished authors enunciated their views, but also to find any descriptions of actual dissection. In the English edition of the ' Regne Animal,' however, the following passage occurs:-"The matrix of the animals of this order (Marsupialia) does not open by a single orifice into the extremity of the vagina, but communicates with the canal by two bent lateral tubes." In 1828 Seiler1 published his observations on a "Kangaroo" which had a mammary foetus in the pouch. He says : - " Noch immer findet man in mehreren neuern Schriften die alte Meinung wiederholt, es entstehe zur Zeit der ersten Geburt des Fotus eine Oeffnung in dem Gebarmutterhalse, gleich hinter der Harnrohren-miindung, durch welche der Embryo geboren werde. So unwahr-scheinlich inir auch immer diese Ansicht erschieu, so sprechen doch Home's Beobachtungen dafiir, und ich untersuchte daher nicht hur die Gebarmutter ganz genau, sondern fullte sie auch von einer Mut-tertrompete aus mit Quecksilber so stark an, dass sie ganz gespannt ausegedehnt wurde: allein es zeigte sich keine Spur einer Oeffnung, unci est ist mir nun gar nicht mehr zweifelhaft, dass der Embryo durch die seitenkanale der Gebarmutter geboren werde, deren Ueber-gangsbildung zu den Eyergiingen Geoffroy St. Hilaire sehr richtig nachweist." In 1834 Prof. Owen2 published his paper " O n the Generation of the Marsupial Animals, with a Description of the impregnated Uterus of the Kangaroo," from which we quote the following passage:- "The foetus has been conjectured to pass into the urethro-sexual cavity by a direct aperture formed after impregnation at the lower blind end of the cul-de-sac; but I have not been able to discover any trace of such a foramen in two Kangaroos which had born young, and besides I find that this part of the vagina is not continuous by means of its proper tissue with the urethro-sexual canal, but is connected to it by cellular membrane only; and the structure is agreeable to what is presented in the simpler forms of the marsupial uterus, as inDidelphys dorsigera and the Petauri, in which the culs-de-sac do not even come 1 Isis, 1828, pp. 475-477. 2 Phil. Trans, cxxiv. 1834, pp. 333-3K4. |