316 Miscellaneous. 
one of the objects for which the bones are hollow, namely, to dimi- 
nish their weight,—the other object being to increase their strength. 
The author proposes to publish his views in a separate form so soon 
as he shall have leisure to complete certain experimental investiga- 
tions that he has devised.—Cambridge Phil. Soc. Feb. 12, 1866. 
On the Organs of Parturition in the Kangaroos. 
By Epmonp ALrx. 
I have lately, by the kindness of M. E. Verreaux, had the oppor- 
tunity of examining the organs of parturition in a female Halmaturus 
Bennettii. This investigation has enabled me to solve a question 
which has long been under controversy. The organs of generation, 
in the female Kangaroo, consist of two ovaries, two Fallopian tubes, 
two uteri, and two lateral vaginze (which, after bending round in the 
form of loops, terminate in the urethro-genital vestibule), and a 
median pouch or vagina. ‘This median vagina, to which our atten- 
tion must be particularly directed, is in the form of an elongated 
cone. The base of the cone, turned towards the uteri, has a wide 
communication on each side with the lateral vagine ; its apex 
advances between these two passages and reaches the bottom of the 
urethro-genital vestibule. Home asserted (Phil. Trans. 1795) that 
there was a direct communication between the cavity of the median 
vagina and that of the urethro-genital vestibule, that the orifice 
enlarged gradually as the period of parturition approached, and that 
it then became capable of sufficient dilatation to allow the escape of 
the foetus. Cuvier did not accept this opinion, his dissections not 
having shown him the orifice indicated by Home. He assumes, in 
consequence, that the foetus gets into one of the lateral vaginze and 
passes slowly along until it is expelled. Owen (Cycl. of Anat. and 
Phys.) has confirmed Cuvier’s assertions; and this opinion has been 
generally adopted. The object of this arrangement of the organs 
would be the multiplication of obstacles destined to prevent the too 
rapid expulsion of so delicate an embryo. 
Nevertheless, if we consider the narrowness of the lateral vagine, 
and especially the extreme fineness which they present at about 
2 centimetres from the urethro-genital vestibule, we may be alarmed 
at the slowness of the passage and the violence of the pressures to 
which this delicate embryo would be subjected. 'There is no more 
argument in favour of the second than of the first opinion ; and the 
observation of facts can alone teach us what is the truth. 
In a preparation which I have submitted to the examination of 
my colleagues of the Société Philomathique, it is easy to see, upon 
the pubic face of the urethro-genital vestibule, immediately above 
the urinary meatus, a circular orifice, larger than that meatus, and 
folded in the manner of the anal sphincter. A sound introduced 
through this aperture, passes immediately into the cavity of the 
median vagina. This preparation furnishes incontestable evidence 
of the existence of the aperture denied by Cuvier and Owen, and 
affirmed by Home. ‘The difference of opinion between these authors 
