aih t a ikl it A tage nli M 
rt 70 gos HT UI E- A A EEC ee EPEE 
of the Mammary Organs of the Kangaroo. 61 
condition, but constitute permanent marsupial teats throughout 
the rest of life. 
If a change in any way analogous to this extraordinary de- 
velopment of the teat in the Kangaroo should be found to occur 
in other animals possessing marsupial bones, it is possible that 
this circumstance may have given rise to the difficulty which 
Meckel and other comparative anatomists (unacquainted with 
this peculiarity) have met with in their endeavours to detect the 
perfect teat in the Ornithorhynchus, upon the supposition that 
young females only had been examined ; since we are informed 
that the mammary gland only has been discovered, while the 
existence of a developed and perfect teat connected with that 
gland has escaped detection. Not having had an opportunity 
of examining that animal myself, I merely offer this as a matter 
of conjecture. 
With these details of the result of my dissection of the mam- 
mary organs and pouch of the unimpregnated animal, I shall 
next point out the differences in the structure of those parts, 
— which I afterwards met with in the dissection of an adult female 
Kangaroo, which was at the time of its death. suckling a young 
one nearly sufficiently grown to leave the pouch. As I had in 
this case an opportunity of examining not only the organs to 
which I have referred, but also other structures connected with 
the functions of those parts, I shall describe their different 
appearances as they presented themselves on examination, in- 
cluding the anatomical peculiarities of the pouch, the marsupial 
bones, and the muscles connected with these and other impor- 
' tant organs. 
I must not, however, omit to express my iratibude to the 
Zoological Society, for the opportunity which was afforded me 
upon this occasion of continuing my investigation ; having been 
most liberally furnished from this source with the subject for 
K 2 making 
