54 CLASS MAMMALIA. 



Petaurus or the Koala. Of such arrangement, might not 

 the uninstructed observer of nature exclaim 



" Serpentes avibus geminentur, tigribus agni." 



A closer observation, however, and a knowledge of the 

 true scientific principles of arrangement, will show that a 

 more accurate classification of those very numerous ani- 

 mals would not have proved a very easy task. All possess 

 some traces of the three kinds of teeth, down even to the 

 ultimate divisions of the Marsupiales, which though devoid 

 of canines, still preserve something of the Carnassial cha- 

 racter in the articulation of the lower jaw. They form 

 a necessary and beautiful link between the order in which 

 they are classed and the rodentia. 



There are certain peculiarities of the cranium mentioned 

 by our author in which these animals agree, as also in the 

 power of rotation in the fore arm, and the want of opposa- 

 bility in the thumb of the anterior extremities. The intes- 

 tines are likewise less voluminous, and the alimentary canal 

 less elongated than in the succeeding tribes ; an admirable 

 provision of nature, to obviate the ill effects of that rapid 

 decomposition to which animal substances are more pecu- 

 liarly liable. 



On the whole, it seems very doubtful, whether for general 

 purposes any better arrangement than that of the Baron 

 can be suggested. Though he has classed together in one 

 order such various animals, yet, in the sub-divisions of that 

 order, their variations of character are completely preserved 

 and clearly distinguished ; and it may well be questioned, 

 if any of these sub-divisions separately possess such leading 

 characters, and still more if the animals which are com- 

 prehended in them be of such importance as to justify their 

 classification into distinct orders. 



It may be said, for instance, that the Cheiroptera are all 



