62 DIGESTION. 



48. The five molar feet ') on each side are divided into two 

 kinds, namely ; two false molars, and three great molars. 



OF INSALIVATION. 



49. During the act of mastication, the food is mixed with the 

 saliva, which phenomenon is designated under the name of 

 insalivation. 



F>g. 20. 50. The safira is a watery fluid, 

 colourless and frothy, which is formed 

 in particular organs, called salivary 

 y lands, (Fig. 20.; 



51. In man, these glands are six in 

 number: three on each side of the face, 

 and are called parotid, sub-maxillary, 

 and sub-lingual. 



52. The parotid glands are the 

 largest; they are placed beneath the 

 skin, between the ear and the jaw, and 

 empty the saliva into the mouth, by a 



long straight tube, which opens on the inside or internal face of 

 the cheeks. 



53. The svb-maxiflarif glands are smaller than the parotid, and 

 are lodged below and behind the lower jaw. 



54. The sub-lingual glands are smaller than the preceding, and 

 are found under the tongue. 



55. The saliva serves to render the deglutition of food more 

 easy, and contributes to accelerate digestion. 



OF DEGLUTITION. 



56. The food conveniently prepared by mastication and insali- 

 vation, unites upon the back of the tongue in a little mass called 

 an alimentary hall, or bolus. 



57. The alimentary ball is next swallowed. We give the name 

 of deglutition to this phenomenon, which consists in the passing 

 of food from the mouth into the stomach, through the pharynx 

 and (Esophagus. 



48. How are the molar feelh distinguished? 



49. What is insalivation ? 



50. What is saliva ? Where is it found ? 



51. How many salivary glands exist in man? 



52. Where art" the parotid glands situated ? Where do they open ? Which 

 of the salivary glands are largest? 



53. What is ihe situation of the sub-maxillary glands? 



54. What is the situation of the sub-lingual glands? 



55. What is the use of the saliva? 



56. What is the alimentary bail or bolus ? 



57. Wfrat is deglutition ? 



