206 



THE ANIMALS AND MAN 



winter, if kept in a cool place, without food or special care 

 of any kind. Observe their swimming and diving, the re- 

 traction of head and limbs into the shell, the use of the third 

 eyelid (nictitating membrane), and the swallowing of the 





FIG. 103. A lizard in the grass. (Photograph from life by Cherry Kear- 

 ton; permission of Cassell & Co.) 



air. Note the "shell," consisting of a dorsal plate, the cara- 

 pace and ventral plate, plastron, and the lateral uniting 

 parts, the bridge. Almost all the fresh-water and land 

 turtles are carnivorous, but few catch any very active prey. 



FIG. 104. The blue-tailed skink, Eumeces skeltonianus. (From life.) 



While some are strictly aquatic others are as strictly terres- 

 trial, never entering the water. The eggs of all are oblong 

 and are deposited in hollows, sometimes covered in the sand. 

 The newly hatched young are usually circular in shape, 

 and differ in color and pattern from the adults. 



The group of lizards (fig. 103) is a very large one, about 



