MASTODON. 613 



Dinotherium that this gigantic extinct Pachyderm was of aquatic 

 habits like the Hippopotamus, and that the inferior tusks served 

 to detach and tear up by the roots the aquatic plants on which 

 it fed. From the apparently superior size of those remarkable 

 teeth in the male, it may be concluded that they also served as 

 weapons of defence and sexual combat. (1") 



PROBOSCIDIANS. 



225. Mastodon. — No family of Mammalian Quadrupeds has 

 suffered more from the destructive operations of time than that 

 which is characterised by the gigantic size of the individuals com- 

 posing it and their peculiar endowment of a long and prehensile 

 proboscis. Two species alone, the Indian and the African Elephants, 

 continue to represent the Proboscidian type in the Mammalian series 

 of the present day ; whilst those that manifested the modifica- 

 tions of the dental system, which gradually reduce the complexity 

 of the Elephantine dentition to the comparative simplicity of that of 

 the Dinothere and Tapir, have long since been blotted out of the 

 series of living beings. The name Mastodon was applied by Cuvier 

 to certain species which, being at the Tapiroid or Dinotherian ex- 

 tremity of the Proboscidian series, manifested modifications of the 

 teeth most meriting to be held generically distinct from those of 

 the existing Elephants : the grinding surface of the molars, instead 

 of being cleft into numerous thin plates, was divided into wedge- 

 shaped transverse ridges, and the summits of these were subdivided 

 into smaller cones more or less resembling the teats of a cow, 

 whence the generic name. (2) A more important modification ap- 

 peared to distinguish the extinct genus, in respect of the structure of 

 the molar teeth : the dentine, or principal substance of the crown 

 of the tooth, is covered by a very thick coat of dense and brittle 

 enamel ; a thin coat of cement is continued from the fangs upon 

 the crown of the tooth, but this third substance does not fill up 

 the interspaces of the divisions of the crown, as in the Elephants. 

 Such, at least, is the character of the molar teeth of the typical, 



(1) For other conjectural uses of the tusks of the Dinothere see the interesting Chapter xiv. 

 in Dr. Buckland's * Bridgewater Treatise.' 



(2) /iftcrroe a nipple, oEovs a tooth. 



