THE OTHER BEASTS 357 



by man, and even domestic animals, such as goats and 

 reindeer will spring upon and kill them. Numbers also 

 die of disease, but they never turn back, they proceed 

 ever onwards to their ultimate destination. 



In Russia and Asia there are two forms of mouse-like 

 animals, specially modified for a subterranean life, having 

 rudimentary external ears, and a short tail, and the 

 claws of the fore-limbs greatly developed. In South- 

 eastern Europe there is a still move completely sub- 



FIG. 93. 



THE MOLE-RAT. 



terranean rodent the mole-rat, tipalax, which is 

 further modified by having its eyes covered by the skin. 

 An African mole-rat is called Baihyergus. Less com- 

 pletely subterranean is the American pouched-rat or 

 " pocket- gopher," which lives and burrows in the 

 plains of the Mississippi, while allied fossorial forms 

 are found in Canada, and America west of the Rocky 

 Mountains. 



The jerboas are creatures with a kangaroo-like habit 

 of progression. Their legs are very long, and the three 

 middle-foot bones, which support their three toes, are 

 anchylosed together into a sort of cannon-bone, as are 



