ARTICLE IV. 



Remarks on the Dental System of the Mastodon, with an Account of some Lomef 

 Jaws in Mr. KocKs Collection, St. Louis, Missouri, where there is a solitary 

 TusJc on the right Side. By W. E. Horner, M. D., Professor of Anatomy in the 

 Uriiversity of Pennsylvania. Read Nod. 6, 1840. 



The extinction of an animal having so many claims to our curiosity as >tlie 

 Mastodon, from its localities — its conformation, and its colossal magnitude — an 

 extinction so complete and final that its fiat has reached not only all the indi- 

 viduals of that genus, but also extended its fatal influence to cognate genera of 

 every description v^ithout exception, is an event in the revolutions of the earth 

 so confounding, that the mind is lost in seeking for a cause, and dwells on the 

 circumstance v^^ith astonishment and awe. An insatiable desire exists for further 

 knowledge on the subject; and we are pleased with almost any attempt to 

 explore the probable history and habits of these animals — their peculiarities of 

 structure — the modifications of development, dependent on their species and 

 genera — and, finally, the particular catastrophe which overwhelmed them at 

 once, or, by a sequence of physical changes in atmosphere and food, brought 

 about their ultimate destruction. It is upon this ground that I propose to offer 

 a few remarks on the Dentition of the Mastodon. 



The data from observations already made, on the phenomena of dentition in 

 these animals, leave the inference that, mechanism and texture excepted, a very 

 close analogy existed between the development of their teeth and those of the 

 Elephant. In the mechanism of the tooth of the Elephant we find vertical, 

 transverse strata of bony matter and of enamel, alternating with one another, 

 and depending for their relation upon an original arrangement of the pulp of 

 the tooth and of its capsule well known to anatomists, and which is partially 



VIII. — o 



