See eee captis ios A im HE uc tr e 
of the Mammary Organs of the Kangaroo. 69 
panniculus carnosus, posteriorly, and above to the tendon of the 
external oblique muscle of the abdomen, while the lower and 
lateral parts of the bag are attached to the mammary gland by 
the medium of its connection with the teat, and to a muscle of 
the gland by cellular tissue. This muscle of the mammary 
gland, which has not hitherto been clearly or correctly de- 
scribed, is situated immediately above the brim of the pelvis, 
lying upon the external oblique muscle of the abdomen. It is 
of a triangular shape, and is attached by a narrow origin to the 
back part of the pelvis, from which point it passes transversely 
round the lower part of the belly. In its course it expands, 
and afterwards divides into two layers, an anterior and a poste- 
rior ; between these the mammary gland is inclosed ; after which 
the fibres of the muscle are continued onwards, and passing 
forward, join with those of its fellow on the opposite side. The 
pair of muscles, therefore, completely encircle the lower part 
of the abdomen, inclosing and enveloping between their fibres 
the mammary gland on each side (tab. 5. f. a.). Neither these 
muscles nor the marsupial bones belong properly to the pouch ; 
since the whole of the pouch may be removed from the abdo- 
minal muscles without disturbing in the slightest degree either 
the muscles I have just described, the glands themselves, or the 
marsupial bones and parts connected with them; the pouch 
being, as I have already stated, nothing more than a fold or 
duplicature of the skin, covered anteriorly by panniculus car- 
nosus and common integument, and sobnase only by cellular 
tissue to the abdominal parietes. 
The real use of the marsupial bones has not hitherto, I believe, 
been clearly explained; nor have I been able to meet with any 
accurate anatomical description of these parts and their sur- 
rounding connections: I consider it therefore necessary, before 
I state 
