5. d 
Li 
of the Mammary Organs of ihe Kangaroo. 81 
sequent period the more perfectly developed young animal has 
ever been known to extract any nutritive fluid from the upper 
and smaller teat. Unless therefore I have recourse to analogy, 
and compare the smaller gland and teat with the supernumerary 
mamme and nipples which we find in other animals, any theory 
which I could suggest relative to their use must be founded 
entirely upon conjecture. 
I have now concluded my cnatomboal description of the mam- 
mary organs of the Kangaroo. At the time I was engaged 
in the dissection of these organs, I was not aware that a de- 
scription had already been published of one of the structures 
described in this paper,—I allude to the compressing muscle 
of the teat,—the existence of which has been noticed by M. 
Geoffroy St. Hilaire, in the Annales des Sciences for 1826, who 
has correctly described its use ; although, from the state in which 
he appears to have received a small portion only of this parti- 
cular part, his dissection does not seem to have afforded him an 
opportunity of tracing the exact extent and attachment of the 
muscle. 
With the exception, however, of the published account of 
M. Geoffroy St. Hilaire’s dissection of these muscular fibres, I 
am not aware that any former anatomist has noticed the pecu- 
liarities of structure which I have described as existing in the 
mammary organs of the Kangaroo. Believing, therefore, that 
many of the facts which I have detailed are entirely new, I have 
been induced to present the foregoing account of my investiga- 
tion to this Society, in the hope that by making them generally 
known, I may be fortunate enough to draw the attention of 
future physiologists more particularly to this interesting branch 
of natural science. 
The facilities which in this country are afforded to those who 
may be inclined to undertake a course of experimental inquiries 
"on XYI. —— E oM | X. upon 
