280 PROF. ST.-GEORGE MIVART ON THE [Feb. 21, 
The female sexual organs have been described by Hunter ; see his 
‘Essays and Observations,’ vol. i. p. 223. 
The drain presents a much less decidedly quadrate form than that 
of the Porcupine (most probably Hystrix cristata) figured by Leuret’'; 
and it is even more smooth, there being but a single short and slight 
depression (or rudimentary sulcus) at the hinder end of the most 
anterior third of the dorsum of each cerebral hemisphere. The 
pituitary body is very large, and the corpora trapezoidea well deve- 
loped. . 
"The brachial plexus* is formed by the sixth, seventh, and eighth 
cervical nerves together with the first dorsal. 
The main part of the eighth cervical, having received a branch 
from the seventh cervical and another from the first dorsal, is 
continued as the median nerve, a smaller branch from the same 
junction constituting the ulnar nerve. The musculo-spiral nerve is 
formed by the smaller branch of the eighth cervical uniting with a 
portion of the seventh cervical. The circumflex nerve arises by two 
roots—one a branch of the sixth, and the other of the seventh, cervical 
nerves. The external cutaneous nerve is formed mainly by a branch 
of the sixth cervical ; but it receives a small filament from the root 
of the circumflex nerve just after the latter has been formed, as above 
stated. The internal cutaneous springs from a branch of the first 
dorsal, which receives a branch from the seventh cervical root of the 
median nerve. 
The luméo-sacral plexus is composed of the last four lumbar and 
the first two sacral nerves. It is very simple, with little interlace- 
ment. The anterior crural nerve is formed by the first two of the 
six, from the junction of which the obturator nerve is also given off. 
The great sciatic nerve is formed by the last two lumbar nerves only ; 
while the small sciatic nerve springs from the junction of the two 
sacral nerves. 
Lims-Muscues or EREetTHIZzON. 
Muscles of the Fore Limb. 
Panniculus carnosus.—The dorsal portion of this muscle is inserted 
into the pectoral limbs partly over the spine of the scapula by 
attachment to the fascia investing the supraspinatus, and partl 
into the outer surface of the humerus (between the deltoid and the 
outer part of the triceps) down to the apex of its deltoid crest. The 
abdominal portion of the same muscle is inserted into the humerus 
outside the greater tuberosity and inside the upper part of the 
deltoid crest. 
The pectoralis is so united with the ventral part of the panniculus 
that they seem like two parts of one muscle. The true pectoralis, 
however, arises from the sternum, and is inserted into the distal 
* See plate iii. of Leuret and Gratiolet’s ‘ Anat. Comp. du Systéme Nerveux.’ 
‘The brachial and lumbo-saeral plexuses were dissected out for me by Mr. 
W. Pearson; and the drawings are from his dissections. 
