THE011Y OF THE EAKTH. 57 



bones are found in our strata, may remain to this 

 day concealed, in some islands not yet discover- 

 ed by navigators, or in some of the vast deserts 

 which occupy the middle of Asia, Africa, the two 

 Americas, and New Holland. 



However, if we carefully examine what kinds 

 of quadrupeds have been recently discovered, and 

 in what circumstances they have been found, we 

 shall see that there is little hope of our ever find- 

 ing alive those which have hitherto been observed 

 only in a fossil state. 



Islands of moderate extent, and at a consider- 

 able distance from the continents or large islands, 

 possess very few quadrupeds, and these, for the 

 greater part, of diminutive size. When they hap- 

 pen to contain any of the larger species, these must 

 have been carried to them from other countries. 

 Bougainville and Cook found no other large qua- 

 drupeds than hogs and dogs in the South Sea 

 Islands ; and the largest species of the West In- 

 dia Islands was the agouti. 



It is true that the great continents, such as 

 Asia, Africa, the two Americas, and New Hol- 

 land, possess large quadrupeds, and, generally 

 speaking, contain species peculiar to each ; inso- 

 much, that whenever large countries of this de- 

 scription have been discovered, which their situa- 

 tion has kept isolated from the rest of the world, 

 the class of quadrupeds which they contained has 



