SKETCH 



HISTORY OF THE MAMMALIA. 



Order— PACHYDERMATA. 



The term Pachydermata was given to the present order 

 by Cuvier, and refers to the thickness of the hide so 

 generally conspicuous in the animals it comprehends; 

 such, for example, as the elephant, hippopotamus, rhino- 

 ceros, hog, &c. 



On looking at the order Pachydermata as a whole, we 

 find it for the most part composed of genera between 

 which there is a want of that intimate relationship which 

 giv.3 us an idea of unity or completeness. We see 

 chasms in the gradation of existing forms, and are forced, 

 as it were, by abrupt transitions from one genus to 

 another, instead of passing through an intermediate series. 

 Yet we are not rashly to infer the original plan and pur- 

 pose of nature to have been destitute of unity. Far 

 from it : happily the researches of the geologist have 

 brought to light the fossil relics of many species, the 

 extinction of which at some remote epoch has left blanks 

 in the series — blanks, however, which we are thus 

 enabled to fill up. And as these researches are con- 

 tinued and extended, we have reason to conclude that 

 every hiatus caused by the absence of intermediate forms 

 will become occupied. In the present order, indeed, the 

 fossil erlics of extinct species are peculiarly valuable and 



VOL. iir. B 



