Miscellaneous. 383 
Other modifications of the complex female organs of the Marsu- 
pials, which have been described* and figured ¢ elsewhere, are equally 
opposed to the hypothesis of the passage of the foetus by a median 
vagina, and prove that, if it ever takes place, it must be by a rare 
exception, the rule in marsupial parturition being the passage of the 
foetus through the lateral loops. 
Whilst thus submitting to the Academy the dates and notices of 
the discovery of an exceptional modification of the median vagina 
in Halmaturus Bennettii, I must remark that the purpose of the 
anatomical section of my Memoir in the ‘ Philosophical Transac- 
tions’ for 1834 was not to confirm a description of Cuvier’s, or to 
refute one of Home’s, with regard to an anatomical fact observed in 
a single species, but to show, by a general review of the entire 
order Marsupialia, that the parts of generation which both these 
eminent anatomists had described as uterine were really vaginal, 
and that the passage which they called the vagina corresponded to 
the urethro-genital canal of other animals. 
To determine the homologies of the complex female organs of the 
Marsupials was the chief object of my anatomical investigations in 
1834. They enabled me to prove that the parts described as Fal- 
lopian tubes (Hometf), or as a ‘‘small portion of a triple or qua- 
druple uterus”’ (Cuvier §), were in reality nothing but the homologues 
of the two distinct uteri, in their totality, of the Rodents; and 
that the succeeding portions, to which the function of gestation had 
erroneously been ascribed, were solely efferent, and answered to the 
vagina of other mammalia. 
It is by the aid of these homologies, expounded in 1834 (and at 
the same time a proof that they have been accepted), that M. 
Alix is now enabled to speak of lateral vagine and of a median 
vagina, although, indeed, the latter is absent in many Marsupials 
and occurs in the form of a cul-de-sac in most of those which 
possess it. 
The mode of transit of the foetus from the vulva to the pouch is of 
so remarkable a character that I cannot accept the merit, which M. 
Alix is so kind as to attribute to me, of having foreseen it. It would 
have been impossible for me to divine the facts @ priori; and even 
had I been endowed with so lively an imagination, I should hardly 
have ventured to present this hypothesis to the Royal Society with- 
out the experiments which gave support toit. I never had any suspi- 
cion of these facts; they were the pure and simple results of obser- 
vation. 
Having isolated a fecundated female of Macropus major, I subjected 
her to a daily examination until I determined the precise period of 
gestation. It is true that I did not see the embryo in transitu. 
He must have eyes differently constituted from mine to discern a 
* In Dendrolagus inustus, Proc. Zool. Soc. 1852, p. 106. 
+ In Aypsiprymnus Whiter, Phil. Trans. 1834, pl. 6. fig. 6. 
{ Phil. Trans. 1795, p. 228. 
§ Legons d’Anat. Comp. tome v. p. 146 (1805). 
