76 ODONTOGRAPHY. 



contained it, was found to exist, In other lower jaws belonging to young 

 animals, which were not opened, the form and capacity of the bone, in the 

 situation of the supposed vertical tooth, did not favor the opinion that 

 any such tooth was lodged in their interior. My impressions, therefore, 

 are not favorable to the opinion, that a vertical premolar tooth, destined 

 to occupy the situation of the second milk-tooth, is to be found in the 

 lower jaw of the Mastodon Giganteus. 



But no one of us has examined the space above the roots of the second 

 milk molar in the upper jaw. We have, from the Eppelsheim fossils, a cast 

 of the upper jaw of a calf Mastodon Longirostris, in which the vertical 

 premolar exists. From the fact of an additional premolar tooth in the upper 

 jaw of the Tapir, and in the Mastodon Angustidens and Mastodon Longi- 

 rostris, we might analogically infer the possibility of the existence of this 

 additional tooth in the upper jaw of the Mastodon Giganteus, without 

 involving the necessity of its existence in the lower jaw. 



ORDER OF THE APPEARANCE OF THE TEETH. 



The teeth of the Mastodon, taken collectively, are of such magnitude 

 and weight, that the co-exietence of the whole number, or even the greater 

 part of them, would, it has been remarked, add much to the extension of 

 the jaws, and require the employment of additional power to support and 

 use them. The substances employed by these animals as food — branches 

 of trees, sometimes of considerable size — must necessarily have produced 

 great detrition of these organs, and thus have rendered them useless before 

 the expiration of the ordinary period of life. Nature has, in consequence, 



