LECTURE VI. 245 



•sidered, it might be looked upon as constituting a 

 link between the proper or viviparous quadrupeds 

 and lizards. The Jerboa and the Kangaroo have 

 the usual actions and attitudes of birds ; generally 

 standing on the hind legs only. The Bats may 

 also be adduced as quadrupeds of an anomalous 

 nature, and possessed of the power of flight ; 

 while the Cetaceous tribe affords a striking instance 

 of the gradual declension of tlie quadruped form, 

 till in the Manati it approaches to that of a very 

 different class of beings. Even among birds there 

 are not wanting some instances of the same sort 

 of indistinct alliance to animals of an opposite 

 cast ; the Penguins, which I have just mentioned, 

 being furnished with wings so very short, covered 

 with feathers so very small, so much resembling 

 scales, and so perfectly useless for flight, that they 

 seem approximated in some degree to fishes, and 

 are capable of exercising with ease and expe- 

 dition no other actions than those of swimming 

 and diving ; since when they attempt to walk, 

 they can merely stagger along in an awkward 

 manner, and if disturbed are liable to stumble and 

 fall. 



The genus Penguin is not very numerous, and 



