XXV111 INTRODUCTION'. 



received its pliocene Mammalia ; and the Zoologist finds 

 this answer to accord with the known powers and habits 

 of those Mammalia. It is true that the Elephant crosses 

 rivers too deep for it to ford; but it swims heavily and 

 slowly, the head and body quite immersed, and only the 

 end of the trunk raised out of the water. The Hippo- 

 potamus has been observed to go a short way out to sea 

 from the mouth of its native African river. " The Tiger 

 is seen swimming about among the islands and creeks in 

 the delta of the Ganges ; and the Jaguar traverses with 

 ease the largest streams in South America. The Bear, 

 also, and the Bison cross the current of the Mississippi."" 5 

 But these facts seem to me to form inadequate grounds 

 for belief that those animals could cross a tidal current 

 of sea, twenty miles in breadth. Still less can we suppose 

 that the ponderous Rhinoceroses, the Hyaenas, Wolves, 

 Foxes, Badgers, Oxen, Horses, Hogs, and Goats; the 

 smaller Deer, Hares, Rabbits, Pikas, or even the aquatic 

 Rodents, could have reached this island from the Con- 

 tinent, if the present oceanic barrier had interposed. The 

 idea of a separate creation of the same series of Mammalia 

 which existed on the Continent, in and for a small con- 

 tiguous island, will hardly be accepted. M. Desmarest 

 deduced an argument in proof that France and England 

 were once united, from the correspondence of their Wolves, 

 Bears, and other species known to have existed in this 

 island within the period of history: the conclusion becomes 

 irresistible when the same correspondence is found to ex- 

 tend through the entire series of Proboscidian, Pachy- 

 dermal, Equine, Bovine, Cervine, Carnivorous, and Rodent 

 Mammalia, which characterized the two countries during 

 the pliocene period of Geology. Thus the science of 

 * Lyell, Principles of Geology, vol. iii. p. 33. 



