230 PROBOSCIDIA. 



the first coarse crushing of the branches of a tree : the trans- 

 verse enamel ridges of the succeeding part of the tooth divide 

 the food into smaller fragments, and the posterior islands 

 and tubercles of enamel pound it to the pulp fit for deglu- 

 tition. The structure and progressive development of the 

 tooth not only give to the Elephants grinder the advan- 

 tage of the uneven surface which adapts the millstone for 

 its office, but, at the same time, secure the constant pre- 

 sence of the most efficient arrangement for the finer commi- 

 nution of the food, at the part of the mouth which is 

 nearest the fauces. 



One cannot contemplate the more numerous lamelliform 

 divisions and subcylindrical subdivisions of the crown of 

 the Mammoth's molar, and the resulting increase of the 

 dense enamel that enters into the formation of the grinding 

 surface, as compared with the teeth of the Indian and 

 African Elephants, without connecting that specific differ- 

 ence of structure with the coarser kind of vegetable food, 

 on which the geographical position of the Mammoth in 

 the temperate regions of the ancient world would most 

 probably compel it to subsist.* 



VARIETIES. QUESTION OF SPECIES. 



The varieties to which the grinders of the Elephant 

 are subject in regard to the thickness and number of their 

 plates, increase in the ratio of the average number of the 

 plates which characterizes the molar teeth of the different 

 species. Thus in the African Elephant, (fig. 88,) in which 



* The reader desirous of full information on the structure, growth, and succes- 

 sion of the teeth of Elephants, is referred to Mr. Corse's and Sir Everard Home's 

 Papers in the 89th Volume of the Philosophical Transactions, and to the ' Ossemens 

 Fossiles ' of Cuvier, torn. i. p. 31. 



