60 DIGESTION. THE TEETH. 



and more solidly fixed. The first are called milk teeth, or 

 deciduous het/t, or tee; h of the frr&t dentition; the second, the 

 permanfiit teeth, or teeth of stc.iud dentition. 



Fiy. 17. 37. The teeth are divided into three kinds, 



17 -) namely: 



38. 1st. The incisive or incisor, which 

 occupy the front of the mouth, and termi- 

 nate in a thin cutting edge, have but one 

 simple root, and are tit for cutting the various 

 C S c c aliments, 



39. 2nd. The canine, which are placed on each side and next 

 to the incisors, are in general, long and pointed; they also have 

 only a single root, but it penetrates deeply into the jaw; their 

 principal use is to fix themselves in the flesh, upon which the ani- 

 mal feeds, and to tear it. 



40. 3d. The molar teeth, or grinders, which are next to the 

 canine, occupy the sides of the mouth ; they are generally, pro- 

 vided with several roots, and present a large, unequal crown, 

 appropriate for grinding the food. 



41. The molar teeth are subdivided into false molar, (dentes 

 biscupidati) and great molar ; the first are smaller than the second, 

 and are situated in front of them; the roots of the great molars 

 are also more numerous, which gives them more solidity and 

 power 



42. The number of teeth varies in different animals. Man, 

 monkeys, the dog, the cat, &c., have the three sorts of teeth, we 

 have just described ; but with the rabbit, the rat, and the other 

 gnawers, (rodentia,) the canine teeth are wanting; and in other 

 quadrupeds, such as the sloth, there are no incisors ; finally, 

 there are also animals that are entirely unprovided with teeth, 

 the ant-eater, and birds, for example. 



Explanation of Fig. 17. The lower jaw of a very young in flint., opened 

 to shuw the capsules ot the teeth. The milk teeth are here developed, and 

 there are fivo on each side: namely, two incisors, (t,?,) one canine, (c.) and 

 two molars, (mm.) ; we see below them the capsules of the incisor, canine and 

 false molar teeth of second dentition, (c,c.) and further back, the capsules o* 

 the great molars, (eg.) 



37. How many kinds of teeth are there? 



38. What are the incisor teeth ? Where are they placed ? What is their 

 peculiar use ? 



3D. Where are the canine teeth ? What is their form ? What is their use ? 

 40. What is the situation and form of the molar teeth ? 

 4J. How are the molar teeth subdivided? 



42. Are the same varieties and number of teeth found in all animals ' 

 What animals are without teeth '/ 



