436 DR. E. C. STIRLING ON THE [Nov. 5, 
had taken place before the specimen came to hand, to which laceration, 
in fact, the above-mentioned attenuation of the cord was due; but 
there were distinct traces of a torn membrane similar to that consti- 
tuting the cord attached to the edge of the umbilical aperture. A 
small coil of intestine protruded at the umbilicus, and no trace of 
allantois was visible external to the body. 
Following the course of the cord to its attachment, it is seen to 
pass through a well-defined orifice of about 2-3 mm. in diameter, 
which opened into the median canal. The edges of this opening 
were longitudinally corrugated. In this median canal the cord be- 
came thicker, and was visibly composed of a semitranslucent tubular 
membrane much crumpled longitudinally ; in its walls ran three 
considerable vessels. Indicaticns of similar vessels could be traced 
back into the shrivelled and attenuated portion of the cord next to 
the embryo; but, owing to the small size of the part of the vascular 
system of the embryo they communicated with, they could be hardly 
distinguished. 
This tubular cord continued though the median canal, which showed 
on the internal surface of its posterior (dorsal) wall a well-marked 
median raphe, rising in its lower part into a ridge of such prominence 
as to mark off two distinct channels ; and proceeding from this median 
ridge were conspicuous transverse and oblique striz, giving the surface 
a partly striated, partly reticulated appearance. The cord lay in the 
right hand of these divisions. The os of each uterus opened into 
the median canal through a prominent nipple-like projection only 
slightly larger than that on the left side, though the body of the 
organ on the right side was several times larger than its fellow. 
Traced through the os into the cavity of the right uterus the cord 
expanded into a thick and much plicated membrane, the folds of 
which dipped deeply down into corresponding sulci of the uterine 
lining. The two structures, however, were easily separable, there being 
apparently no vascular or other organic connection between them. 
Not being able to satisfy myself as to the exact nature of the 
connection between the cord and the embryo in the above specimen, 
on account of its small size and partly torn condition, I referred 
to a larger specimen of an embryo, probably of Macropus major, 
which I happened to possess. From the absence of a record con- 
cerning it, [ am unable to be positively sure either of the species to 
which it belonged or of the conditions under which it was found, but 
for various reasons I have little doubt but that it was a uterine 
embryo belonging to the aforesaid species. This was 25 mm. long, 
exclusive of tail, and closely enveloped in a transparent amnion which 
was reflected from the cord to about an inch which still remained 
attached. 
The substance of the cord itself was formed ofa close, tough mem- 
brane closely adherent to the edge of the umbilical aperture, and it 
concealed a small protruding loop of intestine. In its walls ran three 
vessels, the connections of which with the foetal vascular system I 
need not repeat here, as I found them to be exactly as described vy 
Sir Richard Owen in his ‘ Anatomy of Vertebrates,’ vol. iii. p. 719. 
