HABITS OF KOALA 



143 



The tooth formula of the genus is I f C ^ Pm l M ^-^--g. The 

 additional lower molar seems to be exceptional, and has been found 

 in one specimen only. 



In the alimentary tract the most remarkable structm'e is the 

 large intestine, which is very capacious for the first 28 inches or 

 so of its course. This section of the colon is lined with rugae 

 precisely like those which are found in the caecum. These folds, 

 which at first are some twelve in number, fuse lower down, and 

 by the time that the colon approaches the external orifice are 

 reduced to five. Similar folds, as already stated, occur in the 

 caecum, but do not extend as far as its blind end. The caecum 

 is proportionately and actually larger than in any other Marsupial. 

 The gall-bladder is unusually elongated. 



The Koala is mainly crepuscular or nocturnal in its habits. It 

 feeds so exclusively upon the leaves of the gum-tree {Eucalyptus) 



Fig. 70. — Koala. Phascolarctos cinereus. 



that it is impossible to keep the creature long in captivity in 

 lands where that particular kind of food is not available. 



The female, though she seems to bear but a single young one, 

 which is carried on the back after the fashion of some Opossums, 

 has two nipples. The animal's slow habits seem to require a 

 nocturnal and retired life. It is about as lethargic as the 

 Sloth, and it is said to fmrther resemble that animal in clinging 

 firmly to a branch even after it is shot. 



