158 



ANATOMY AND PHYSIOLOGY. 



Somewhere between the completion of the seventh and eighth 

 years, the second dentition commences. The first permanent grinders 

 appear, and the central incisors fall out and are replaced. In three 

 months more, the lateral incisors follow. In from six to twelve 

 months more, the grinders give way, and after them the eye-teeth. 

 The grinders are succeeded by a new species of teeth, which do 

 not exist in the milk set, called the small grinders. These changes 

 take place about the tenth or eleventh year, and it is not for two or 

 three years more that the second of the permanent grinders makes 

 its appearance. A long interval now succeeds, and the jaw acquires 

 its full proportion, and about the nineteenth or twentieth year the 

 wisdom tooth cuts the gum, but sometimes not till even a later 

 period. \Yisdom teeth sometimes appear at thirty. The grinders 

 often give pain in coming through, on account of their broad sur- 

 faces meeting with much resistance. The following is a view of 

 the teeth, fangs, and nerves. 



STOMACH. 



j. ne stomach is a bag of a conical shape ; the large end of 

 which lies in the left side of the belly immediately beneath the 

 diaphragm, and the small end at the hollow, which is familiarly 

 known as the pit of the stomach. It is bent besides on account of 

 its passing across the spine ; the concave border being directed 

 backwards, and the convex border forward. When the stomach is 



