104 ANIMAL BIOLOGY 



1. Seize the posterior or hind end of the tongue and pull 



it forward. 

 a. Tell what you have done and state which end of 



the tongue is attached to the floor of the mouth. 

 6. Describe the shape of the tip end of the tongue. 



2. The living frog can extend its tongue much farther 



than you have been able to do in the case of 

 the preserved frog, and in the living frog the 

 tongue is covered with a very sticky substance. 

 The tongue is used to catch insects at some 

 distance from the animal (Fig. 79). Tell how 

 you think the frog could use its tongue to catch 

 insects and get them into its mouth. 1 



3. Look for teeth on the jaws of a skeleton of a frog, 



or if you cannot obtain a skeleton, rub the finger 

 over the jaws of a preserved specimen. 



a. Which of the jaws has teeth? 



b. Describe the location of the teeth on the jaw. 



c. State the shape and size of the jaw teeth. 



d. What is the probable use of the jaw teeth? 



4. (Optional.) Look on the roof of the mouth for two rela- 



tively large palate teeth. Rub the fingers over the 



surface of the palate teeth. 

 a. Tell what you have done. 



6. What have you found out about the palate teeth? 

 c. What is the probable use of the palate teeth ? 



H. How a frog swallows. 



1. Gently touch the eyes of a living frog until it draws 



them into the head. Tell what you have done 

 and observed. 



2. Look at the roof of the mouth of a preserved speci- 



men while you push the eyes into the head. 

 Tell what you have done and describe the effect 

 produced in the roof of the mouth. 



3. How will the act of pushing the eyes into the head 



be useful to a frog in swallowing ? l 



*If possible live frogs should be fed on meal worms, or other 

 insects, and the feeding movements observed. 



