TORTOISES AND TURTLES. 31 



perhaps rest in their slowness of motion. Their 

 unarmoured neighbours escape by flight, a way- 

 which is impossible to these sluggish creatures. 



Land-tortoises may be readily distinguished 

 by their feet. The toes are very short, with no 

 trace of webs between them, and the hind-feet at 

 least are club-footed. The peculiar form of these 

 feet is the outcome of adaptation to the support 

 of the remarkably heavy and inflexible body. 

 To the weight and immobility of the trunk we 

 may attribute the fact that the creatures are 

 confined to the earth. Tree-climbing to them is 

 an impossibility. They may delve below the 

 surface, but they cannot rise above it. But this 

 by the way. 



The outer surface of the legs is covered with 

 little horny scales, covering, in many cases, bony 

 nodules, so that when drawn into the shell the 

 mouth and hinder apertures thereof are effectually 

 protected against attack. In some cases, as we 

 have already remarked, these apertures are closed 

 by raising the ends of the breast-plate. 



Comparisons are said to be odious. Applied 

 to human affairs this is often true. In natural 

 history it is otherwise. Let us then contrast the 

 method of barricading practised by the Tortoise 

 with that of the remarkable South American 

 mammal, the Armadillo. This animal, like the 

 Tortoise, is encased in bony armour covered with 

 horny plates. The great back-shield differs from 

 that of the Tortoise among other things in its 

 great flexibility, so that, having no breast-plate, 

 the animal can curl itself up into a ball, leaving 

 but a single aperture, which is closed by the tail 



