1889.] ANATOMY OF THE KANGAROO. 437 
The allantois was represented by a shrivelled cord-like structure ter- 
minating ina blunt club-like extremity, lying alongside the other 
constituents of the cord and easily separable from them. This 
allantois was continuous with the fundus of the bladder, from which 
it extended 8 mm. 
Along with the question of the route outwards of the embryo has 
been discussed also the route inwards of the seminal fluid, whether, 
in fact, this goes by the lateral canal or by the median canal when 
this is open. I am able to throw some light on this point (at least 
for Macrepus major) by the receipt recently of a specimen of the 
female organs of an adult of this species shot immediately after an 
observed act of coitus. 
In this specimen, which is represented in the drawing (fig. 2, p. 438) 
about one half of the natural size, the lateral canals were enormously 
distended by what proved to be six and a quarter ounces (by weight) 
of a viscid tenacious mucus-like substance containing abundant sper- 
matozoa. The median canal was also distended to a size which would, 
in its upper part, more than contain two good-sized thumbs, and which 
contained some of the same kind of mucus-like material as that in © 
the central canals, the mass in each being continuous. In its lower 
third the median canal narrowed down to a size that would scarcely 
admit a pencil. 
The opening between the median and each lateral canal was very 
large and patent, admitting a large thumb easily. Both anterior 
(ventral) and posterior (dorsal) walls of the median canal were no 
thicker than stout parchment, and the internal surface of the former 
showed a distinct median raphe, which, asin the preceding specimen, 
rose into such a well-marked ridge in the lower part as to divide the 
passage into two similar well-marked channels. The same striated 
and reticulated appearance of its walls in the lower part also existed. 
Between the median canal and the urogenital passage there was a 
well-defined but small passage that would barely admit an ordinary 
steel knitting-needle. Seven mm. below this aperture, on the an- 
terior (ventral) wall of the urogenital passage, was the orifice of the 
uretha (u, figs. 2 & 3); and between these two openings extended a 
laterally compressed keel-like projection (vide figs. 2 & 3,f), 5 mm. 
in height, thin at its free edge, springing from a base (6 mm. long 
and 3 mm. wide) from the posterior (dorsal) surface of the urethra. 
In fact the arethra might be described as piercing longitudinally the 
base of this projection. Both the urethral orifices and this keel-like 
ridge occupied a narrow ellipsoidal and depressed area marked off by 
a well-marked (9, fig. 3) ridge of corresponding outline. 
Situated in the middle line, exactly midway between the orifice of 
the urethra and the joint outlet of the combined urogenital and 
rectal canals, was a flat tongue-like process (Y, fig. 2), compressed 
dorso-ventrally and pointing inferiorly towards the outlet of the 
passage. This covered up a cul-de-sac, which extended upwards 
under it for 5-6 mm., and with a similar width. On the posterior 
dorsal surface of this tongue-like flap was another smaller cul-de-sac, 
leading upwards also for about 3 mm., and with about the same 
