of the Mammary Organs of the Kangaroo. 6^ 



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. n -k. n; , ,o, . 



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, \ 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 gratitude 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 



