NATURAL HISTORY. 



and in the spring the residue is greedily devoured by Wild Pigs and Bears. Even the poorer human 

 inhabitants of the countries frequented by the Ground Squirrels do not disdain to eke out their scanty 



means of subsistence by plundering the hoards of these animals. 

 Many of them perish in severe winters, great numbers are destroyed 

 by man, by the smaller Carnivora, and by birds of prey, but, neverthe- 

 less, they manage to hold their own, in consequence of the great fertility 

 of the females, which produce several young twice in the year, namely 

 in May and August. At pairing time the males fight violently. 



From the Ground Squirrels we pass, by a perfectly natural transi- 

 tion, to the MARMOTS (Arctomyinai), the second sub-family of Sciuridse. 

 These animals differ from the preceding forms by their broader 

 incisors, shorter tail, and stouter form of body, and by having the 

 third finger longer than the rest. The first upper molar, also, is larger 

 and more persistent than in the Squirrels, and the other molai-s 

 The Marmots are all terrestrial animals, living and storing provisions 

 in burrows, which they dig in the ground, and they are strictly confined to the northern parts of 

 the two hemispheres. 



The nearest approach to the Squirrels is made by the SPERMOPHILES (Spermophilus), several 

 species of which occur in North America from Mexico to the Arctic regions, but never to the east of the 

 great central prairie region ; whilst in the Old World their domain extends from Silesia, through 

 Russia, and across Asia, to the Amoor and Kamstchatka. The Spermophiles are Squirrel -like in form 

 and have rather short tails, but in the American species this organ is generally longer than in those of 

 the Eastern continent. On the thumb the claw is either very small or altogether wanting ; the two 

 series of molars are nearly parallel, and the mouth is furnished with large cheek-pouches. The 

 ears are very small. These animals live in society, and prefer a dry, sandy, or loamy soil, in 

 which they can easily make their burrows, which terminate in a chamber lined with grass and 

 herbage, and have, besides, side-chambers, in which provisions can be stored for winter use. Like 

 the other species of the family, the Spermophiles pass the winter in a state of partial torpidity. 

 In the summer they are exceedingly lively and playful. Their food consists of roots, berries, and 

 seeds of various kinds, and their winter stores of these articles are carried into the burrows in 



MOLAB TEETH OF THE MARMOT. 



differ in structure (see figure). 



STRIPED SPERMOFHILE, OR GOPHER. 



