1889.] ANATOMY OF THE KANGAROO. 43/ 



The allantois was represented by a shrivelled cord-like structure ter- 

 minating in a 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 tiie median canal when 

 this is open. I am able to throw some light on this point (at least 

 for Macropus mnjor) 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 liaif of tlie natural size, the lateral canals were enormously 

 distended by wliat proved to be six and a quarter ounces (Ijy weight) 

 of a viscid tenacious mucus-like substance containing abundant sper- 

 matozoa. Tiie 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 

 tiiicker than stout parchment, and the internal surface of the former 

 showed a distinct Tuedian raphe, which, as in the preceding sjiecimen, 

 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 adinit 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 (m, figs. 2 & 3) ; and between these two 0])euings 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 (G mm. long 

 and 3 mm. wide) from the posterior (dorsal) surface of the urethra. 

 In fact the urethra 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 (rj, 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-veutrally and pointing inferiorly towards the outlet of the 

 passage. This covered up a cul-de-sac, which extended upwards 

 luiiler 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 



