112 FOSSIL MAMMALIA. 



might thus repose, moored to the margin of a lake or river, 

 without the sUghtest muscular exertion, the weight of the 

 head and body tending to fix and keep the tusks fast an- 

 chored in the substance of the bank ; as the weight of the 

 body of a sleeping bird keeps the claws clasped firmly 

 around its perch. These tusks might have been farther 

 used, like those in the upper jaw of the Walrus, to assist in 

 dragging the body out of the water; and also as formidable 

 instruments of defence. 



The structure of the scapula, already noticed, seems to 

 show that the fore leg was adapted to co-operate with the 

 tusks and teeth, in digging and separating large vegetables 

 from the bottom. The great length attributed to the body, 

 would have been no way inconvenient to an animal living 

 in the water, but attended with much mechanical disadvan- 

 tage to so weighty a quadruped upon land. In all these 

 characters of a gigantic, herbivorous, aquatic quadruped, 

 we recognise adaptations to the lacustrine condition of the 

 earth, during that portion of the tertiary periods, to which 

 the existence of these seemingly anomalous creatures ap- 

 pears to have been limited. 



SECTION II. 



MEGATHERIUM. 



As it will be quite impossible, in the present Treatise, to 

 give particular descriptions of the structure, even of a few 

 of the fossil Mammalia, which have been, as it were, re- 

 stored again to life by the genius and industry of Cuvier; I 

 shall endeavour to illustrate, by the details of a single 

 species, the method of analytical investigation, that has been 

 applied by that great philosopher to the anatomy both of 

 fossil and recent animals. 



