280 LIVING AND EXTINCT ELEPHANTS. 



he commits great havoc upon sugar cane, rice fields, plan- 

 tains, and many other cultivated plants ; * but these incidents 

 form only interludes in his established alimentary habits. 

 His dung in the wild state commonly presents a large pro- 

 portion of contused and undigested woody fibre, in a stringy 

 form, mixed up with other vegetable tissues. 



It is difficult to conceive of a mechanism better adapted to 

 the duty which they have to perform than is presented by the 

 molars of the Indian Elephant. Taking the three true 

 molars, which serve during the adult stage of the animal, 

 they are composed successively of 12, 16, and 24 ridges. 

 Each ridge has the core formed of a high wedge-shaped plate 

 of ivory ; a continuous plate of enamel is closely folded over 

 these wedges, which are confluent at their base ; and the 

 intervals between the ridges are filled up, each with a re- 

 versed wedge of cement, which is insinuated between the 

 grooves and inequalities of the enamel. When the crown is 

 in full activity of wear, the penultimate molar, consisting of 

 sixteen ridges, presents an miequal triturating surface, com- 

 posed of thirty-two plates of enamel, alternating with sixteen 

 thin wedges of ivory and as many of cement, making in all 

 sixty-four alternations, disposed within a length of from 8-^ 

 to 9-g- inches. The disintegrating and bruising power of the 

 surface is further greatly augmented by the circumstance, 

 that in the Asiatic Elephant the plates of enamel are folded 

 vertically into a number of bold close-set zig-zags, or undu- 

 lations, which present a crimped edge during wear. If a 

 number of these plates were brought together, so as to place 

 their undulations in contact, an appearance woidd be pro- 

 duced analogous on a large scale to the engine-turning of a 

 watch-case, arranged in longitudinal lines. The three con- 

 stituent materials being of unequal hardness, the cement is 

 worn lowest, the enamel highest, and the ivory to a level 

 between the two. A constant equilibrium is maintained, in 

 the normal state, between the nature of the food, the waste 

 of the crown-surface, the absorption of the fangs, the forward 

 movement of the body of the tooth, and the replacement of 

 the worn-out portion by a succession of fresh plates, pro- 

 truded from behind. 



This goes on hi the wild state, but no sooner is the animal 

 kept in captivity than the balance is upset, and the whole 

 mechanism put out of gear. Instead of grass culms and 

 leaves charged with silicious crystals, or mechanically mixed 

 with sand, and of tough woody fibre and bark, requiring a 

 powerful process of trituration to fit them for deglutition, 



1 Corse, Asiat. Researches, vol. iii. p. 229. 



