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mals, have their roots brought into use when the crown is worn away ; 

 and as the root divides into two branches, the two stumps of the roots of 

 one tooth, forced upwards by the filling up of the alveolus, will give the 

 appearance of two teeth. 



In the lower jaw are two large incisors, placed at the anterior angle ; 

 and between these are two very small incisive teeth, which remain con- 

 cealed within the gums. There are also two large incisive teeth in the 

 upper jaw; and Cuvier has discovered, that in this jaw also there are 

 two very small incisors, which are disposed, contrary to those of the lower 

 jaw, on the outside of the larger incisors. 



The differences observable in separate detached grinders of these ani- 

 mals are not such as will serve to distinguish the species, but merely to 

 point out the age of the individuals. Of course, it is not from the fossil 

 grinders alone that we are able to determine whether the fossil remains 

 of this animal belong to a species which still exists, or to one which is lost. 

 Happily, however, complete information may be obtained on this point 

 from the examination of the whole skull. By a careful comparison of the 

 fossil with the recent skull, it is found that the fossil skulls exactly agree 

 with each other, and belong to one and the same species, and that the 

 fossil species is essentially different from those which are known in a living 

 state. 



Omitting to notice the opinions of those who had written on this sub- 

 ject before the necessary anatomical knowledge respecting the living 

 species of this animal was attained and published, I shall place before you 

 a sketch of the .observations of M. Cuvier, on the opinions entertained by 

 M. Faujas on this subject. 



There appeared to be three living species of rhinocers : 1 . That of 

 India, a unicorn, with a rugous coat, and with incisors, separated, by a 

 space, from the grinders. 2. That of the Cape, a bicorn, the skin with- 

 out rugse, and having twenty-eight grinders, and no incisors. 3. That 

 of Sumatra, a bicorn, the skin but slightly rugous, thus far resembling that 

 of the Cape, but having incisive teeth like that of India. 



