ODONTOGRAPHY. 63 



The consideration of these facts will show the value of the figures 

 formed by the enamel on the extremities of the cusps, as expressing specific 

 characters. 



The number of the teeth was long involved in mystery. The genius Number. 

 of Cuvier opened the way to a knowledge of their number, differences, and 

 development. He advanced no farther in the path he had opened than 

 to the fourth, or, at the utmost, fifth tooth ; making the whole number to 

 be from sixteen to twenty, exclusive of the great incisors or tusks. 



In 1831, Dr. Hays, the distinguished editor of the " American Journal 

 of the Medical Sciences," read a paper to the American Philosophical 

 Society, in which he described various jaws of the Mastodon Giganteus, 

 and the teeth contained in them. He seems to have been the first writer 

 who clearly pointed out the probability, that the number of these teeth was 

 six on each side of each jaw in the Mastodon Giganteus, and, of course, the 

 whole number twenty-four. He says, " The whole number of teeth pos- 

 sessed by the animal described by Dr. Godman (Tetracaulodon) is, then, at 

 least twenty ; and we think that it is at least probable, that the animal 

 possessed an intermediate tooth between the second tooth with three deu- 

 ticules, and that with four denticules." " Should we be correct in our views, 

 this animal possessed three teeth, with three denticules in each side of 

 each jaw, making the whole number of teeth twenty-four ; but to render 

 this certain would require specimens of intermediate ages to those hitherto 

 described." These have since been obtained, and have fully confirmed 

 the opinion suggested by the sagacity of Dr. Hays. In the collection 

 of the Cambridge University, there is a series of jaws affording a perfect 

 demonstration of this fact, and settling the number to be twenty-four. 

 Professor Horner, in a paper read to the Philosophical Society, thought 



