272 PROBOSCIDJA. 



the tropical regions of Asia and Africa ; and we have seen 

 in the preceding section, that an extinct species of this 

 genus once ranged over the whole of the temperate, and 

 part of the arctic zones of the northern hemisphere of the 

 globe, and has left abundant evidence of its former exist- 

 ence in our own island. 



In like manner we learn from the study of fossil re- 

 mains, that other quadrupeds, as gigantic as Elephants, 

 armed with two as enormous tusks projecting from the 

 upper jaw, and provided with a proboscis, once trod the 

 earth ; the presence of the latter flexible organ being 

 inferred, not only by its necessary coexistence with long 

 tusks, which must have prevented the mouth reaching the 

 ground, but also by the configuration of the skull, by the 

 holes which gave passage to large nerves, and by depressions 

 for the attachment of particular muscles, analogous to those 

 which relate exclusively to the organization of the trunk in 

 the Elephant. Like the Elephants, also, these other huge 

 proboscidian quadrupeds were destitute of canine teeth, 

 and provided with a small number of large and complex 

 molar teeth, successively developed from before backwards 

 in the jaws, with a progressive increase of size and com- 

 plexity, from the first to the last. The broad crowns 

 of the molar teeth were also cleft by transverse fis- 

 sures ; but these clefts were fewer in number, of less 

 depth, and greater width than in the Elephants : the 

 transverse ridges were more or less deeply bisected, and 

 the divisions more or less produced in the form of udder- 

 shaped cones, whence the name Mastodon,* assigned by 

 Cuvier to the great proboscidian quadrupeds with teeth 

 of this kind. 



A more important difference presents itself when the 



* Etym. Gr. maslos, udder, odos, a tooth. 



