42 KIND 0V FOOD INDICATED BY THE TEETH. 



only on the anterior surface of the tooth, so that the pos- 

 terior surface being soon worn down, the tooth has a 

 bevelle'd edge. But without some contrivance or other, 

 this thin edge though composed of enamel would yield, 

 and the tooth be at last worn down to the gums. To 

 obviate these inconveniences, the teeth are furnished 

 each with a very long root which grows upward and sup- 

 plies the waste of the crown. In some of these animals 

 they have a prodigious length, extending backwards nearly 

 to the angle of the jaws. 



Emily. Those animals have no canine teeth, and 

 neither, if I am r.)t mistaken, have the horse and ox ; 

 at least there is a space in their jaws where the canine 

 should be, and it is here that the bit is received in the 

 former animal. 



Dr. B. You are right ; and not only are the canine 

 sometimes wanting, but also the molares. In the dol- 

 phins of various kinds, the teeth which amount frequently 

 to two hundred in number, are all canine. In Fishes 

 too, they are all canine. You have seen many times 

 these terrible instruments in the jaw bones of sharks, 

 where the points are extremely sharp, and the edges 

 serrated. And to render them still more efficacious, 

 they have the power of raising or depressing them at will. 

 You want no one to teach you that their food must be 

 exclusively flesh. 



Emily. So then by a simple inspection of the teeth 

 you believe we may ascertain whether an animal lives- 

 on flesh, or a vegetable diet. 



Dr. B. Yes ; and where it subsists on a mixed diet 

 we can tell with some certainty the proportion of each. 



Emily. If that be the case then, why may we not 

 Bottle the long agitated question, whether man was des- 

 tined by nature to live on an exclusively animal or vege- 

 table diet, or on a mixed diet of both. 



Dr. B. It cannot be determined from the form of 

 die teeth only, for the reason that nearly all the food of 

 man except ripe fruits, undergoes the preparation of 



