COMPARATIVE ANATOMY OP THE TEETH. 269 



department of scientific and practical research ; and their 

 labors have already been crowned with the most useful 

 and happy results. 



Cuvier and Owen, with many others, have shown that 

 the teeth of all animals obey the same fixed and immutable 

 law of limitation in their form, size, structure, function, 

 and duration in a word, that all the essential elements of 

 their organization are obedient to, and governed by the 

 same general laws. Still further, the teeth are now re- 

 garded as forming the most secure basis for classifying the 

 animal kingdom; for every class of animals having the 

 form of its teeth differing from that of every other class, we 

 readily recognize the distinction, and obtain a foundation 

 of classification superior to any other while from the 

 great durability of these organs, and their superior resist- 

 ance to the process of decomposition, the geologist is fur- 

 nished with a key by which he can unlock the history of 

 the past, and testify, not simply of the existence of ani- 

 mals long since extinct, but accurately classify, and faith- 

 fully describe their habits, food, and other peculiarities. 

 To the dental student, therefore, an acquaintance with 

 comparative dental anatomy, as far as his opportunities 

 will allow, becomes a matter of great interest, and should 

 always hold a high rank among the various studies per- 

 taining to his profession. 



We do not, by any means, however, intend to enter into 

 any lengthy detail on comparative dental anatomy; for 

 such an attempt would be entirely incompatible with the 

 limits of the present work, as well as altogether unneces- 

 sary since the publications of Owen, Blandin, and others. 



All that we propose here, is simply to give such a general 

 outline as may induce every student to examine the sub- 

 ject for himself, and so to estimate the value of such 

 knowledge as to be persuaded to devote all, or as much of 

 his leisure moments as he can spare to its study and 

 investigation. 



The extent of the dental organs proper seems to be lim- 

 ited to the vertebrated division of the animal kingdom, or 



