THE LIZARD 79 



Watch the animal breathe. How frequent are the res- 

 pirations ? Describe the breathing movements. 



C. EXTERNAL FEATURES. Note the four divisions of 

 the body, head, neck, trunk, and tail. How does this 

 body division differ from the frog's ? 



Note the number of legs and compare them with those 

 of the frog. How do the hind legs of the lizard compare 

 in size with the front ones ? 



The fore legs arise behind the neck, and each one consists 

 of the upper arm, the forearm, and hand, which has five 

 fingers. Make out these parts. 



The hind legs also consist of three parts, thigh, shank, 

 and foot. How many claws on each foot? Is there any 

 difference in the length of these claws? Note the situa- 

 tion of the " big- toe " claw. The hind legs arise from the 

 trunk more ventrally than the front ones. 



Make a drawing of a hind leg showing all the parts. 



What is the color of the body above and below ? How 

 many lines are on the body ? Where are they situated ? 



Note that the body is covered with scales. How does 

 this feature compare with the frog ? Study the shape and 

 arrangement of the scales on the head, back, tail, and belly. 

 How many longitudinal rows of scales on the ventral sur- 

 face? On some species the scales are not in longitudinal 

 rows on this surface. 



Note that the mouth is wide but that the jaws are not 

 dilatable like those of the snake. Find the nostrils on the 

 sides of the end of the head. They open into the mouth. 



Back of the corners of the mouth note the tympanums 

 of the ears. They are plainly visible. 



The upper and lower jaws are each furnished with a row 

 of small, conical teeth. 



