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angles of the fold are continued into the margins of the penis, which projects from be-
low the external orifice of the urethro-sexual cavity into the vestibular of outer com-
partment of the cloaca. The penis rapidly diminishes to a point, and its extremity is
spirally retracted ; when stretched out, the whole length of the intromittent organ is
1 inch and a half in length ; but this, doubtless, falls short of the dimensions of the penis
in the recent and erect condition. An urethral groove traverses the upper, or what, if
the penis were drawn out of the cloaca and bent forwards along the abdomen, would be
its under surface, by an urethral or rather seminal groove, which is continued to the end
of its spiral extremity : the margins of this groove are not beset with papilloe, but simply
wrinkled transversely, as in the Emeu and Ostrich. The two lateral cavernous crura of
the penis are attached to the membranous parietes of the uro-genital cavity, and to a re-
tractor or erector muscle which comes off from the inner surface of the lower edge of
the ischium : one of these muscles is represented at Pl. III. n, fig.3. The base of
the penis is drawn towards the coccyx, and the veins quitting the corpora cavernosa are
compressed by a second pair of muscles (o), narrower but thicker than the erectors,
which arise from the fascia at the sides of the coccyx, pass downwards along the sides
the vestibule, and meet at a tendinous raphe on the dorsum penis. Immediately above
the base of the penis, on each side, there is a considerable plexus (p) of both arteries
and veins, with which also many filaments of nerves are intermingled. The last-
described muscles cross over the base of this plexus in their course to the penis, and
would doubtless impede, if not arrest, the current of blood in the veins ; they might be
termed, therefore, "compressores venarum penis," as they fulfill the same office as the
compressores described by Douglas in the Dog. In the office of maintaining the erect
and turgid state of the intromittent organ, the compressores are aided by two broad
sphincters : the internal one (Pl. III. q, fig. 3.) rises from the sides of the coccyx, and
more immediately surrounds the cloaca, meeting its fellow at the middle line of the in-
ferior surface : the external sphincter (r) closes principally the external compartment
of the cloaca.

The female organs in the specimen dissected presented their full functional develop-
ment. the left ovarium was, however, too much decomposed to admit of any accurate
observation of its structure being made : it consisted of an irregular and obscurely di-
vided mass, of about three inches in length by two in thickness : the largest yelks ap-
peared to have been about one inch in diameter. There was a perfectly distinct right
ovarium situated in front of the corresponding supra-renal gland ; it consisted of an ir-
regularly oval flattened body, with a slightly granulate surface, nine lines long, six lines
wide, and about one line in thickness. the part of the cloaca where a rudimental right
oviduct, supposing one to have been present, might have terminated, was cut away.

The left oviduct was of large size, and from the condition of the lining membrane of
the calcifying segment of uterus, seemed to have been exercising its function a brief pe-
riod before death. The whole length of the oviduct was thirteen inches ; it was disposed

E