TONGUES OF REPTILES. 129 



The tongue of the frog is of great length ; its 

 root is attached close to the fore part of the 

 lower jaw, while its point, which is cloven, is 

 turned backwards, extending into the throat and 

 acting like a valve in closing the air passage 

 into the lungs. If, when this animal has ap- 

 proached within a certain distance of the insect 

 it is about to seize, we watch it with attention, 

 we are surprised to observe the insect suddenly 

 disappear, without our being able to perceive 

 what has become of it. This arises from the 

 frog having darted out its tongue upon its victim 

 with such extreme quickness, and withdrawn it, 

 with the insect adhering to it, so rapidly, that it 

 is scarcely possible for the eye to follow it in its 

 motion. The Chameleon also has a very long 

 and slender tongue, the extremity of which is 

 dilated into a kind of club, or spoon, and covered 

 with a glutinous matter : with this instrument 

 the animal catches insects from a considerable 

 distance, by a similar manoeuvre to that prac- 

 tised by the frog.* 



Serpents and Lizards have generally curved 

 or conical teeth, calculated rather for tearing and 

 holding the food, than for masticating it : like 

 those of fishes, they are affixed partly to the 



* Mr. Houston has given a description of the structure of this 

 organ, and of the muscles by which it is moved, in a paper con 

 tained in the Transactions of the Royal Irish Academy, vol. xv. 

 p. 177. 



VOL. IL K 



