TOOTHLESS QUADRrPEBS. 131 



Their long hind legs enabln them to taku enormous springs, during 

 whLoli tlveir tails serve to balance them. Indeed, a jerboa, when 

 deprived of its tail, is afraid to leap. At first sight the Jerboa 

 seems to alight on its hind feet, as well as spring from them, but 

 the fact is, that it alights on its fore feet and draws up the hind 

 legs ready for the next leap with such rapidity that the eye can 

 scarcely follow the movement; as has been elsewhere related of the 

 kangaroo. The foot of the Jerboa is defended by long bristly 

 hairs, which not only give the creature a firm hold of the ground 

 for its spring, but also defend the foot from the burning soil on 

 which it lives. The timidity of the Jerboa is very great, and on 

 the slightest alarm it instantly rushes to its burrow, but if inter- 

 cepted, skims away over the plain with such rapidity that it seems 

 to fly ; and when at full speed a swift greyhound can scarcely over- 

 take it. Grain and bulbous roots are its chief food ; while eating, 

 it holds the food with its fore paws, and sits upright on its 

 haunches, like the squirrels and marmots. The Jerboa does not 

 bear confinement well ; it always appears uneasy and distrustful ; 

 it remains hidden during the day, and even when it emerges from 

 its concealment towards the evening, is always ready to retreat at 

 the least alarm. There are many kinds of jerboa; the Egyptian 

 Jerboa is rather small, being about the size of a large rat ; its color 

 is a tawny yellow. 



TOOTHLESS QUADRUPEDS. 



The Edentata, or Toothless Quadrupeds, include the 

 Ant-eaters and the Pangolins, which possess no teeth at all, and 

 the Sloths, Armadilloes, etc., which have back teeth, of a peculiar, 

 but imperfect structure. 



There are two species of the Sloth, the Vhau, or two-toed, 

 which has no tail, and only two nails on the fore feet; and the Ai, 

 or three-toed, which has a short tail, and three nails on each foot. 

 These animals have neither incisive nor canine teeth ; their eyes 

 are dull and heavy ; their mouths wide and thick ; their fur coarse 

 and staring, and like dried grass; their thighs seem almost dis- 

 jointed from the. haunch ; their legs very short, and badly shaped ; 



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