222 



DIGESTION AND ABSORPTION 



of a frog with that of a man. In what respects are they similar ? 



Different ? 



2. Of what uses might the ridges in the stomach be? The 



folds and villi in the intestine? (Remember the purpose of the 



food tube is to prepare food to become part of the blood.) 



Drawing. — Draw the food tube and glands of the frog and 



show all parts. On the same page, using the manikin, draw the 



food tube and glands 

 of man. Label all 

 parts of drawings. 



Problem 185: To 



study my own teeth. 



Materials. — A mir- 

 ror, teeth. Figure, 

 page 301, Civic Biology. 



Method. — Using a 

 small mirror, count 

 your teeth, giving the 

 number under each of 

 the following heads : 



(a) Incisors, broad 

 cutting teeth in front. 



(b) Canines, pointed 

 sharp teeth next to 

 the incisors. 



(c) Premolars, grind- 

 ers with two points on 

 the biting surface. 



(d) Molars, teeth 

 with more than two 

 points, in the back of 

 the mouth. 



Observations. — 

 What are the numbers 

 and uses of each of the 

 above kinds of teeth ? 



