24:0 FROM NORTH POLE TO EQUATOR. 



To a slight extent migrations take place among all mountain 

 animals. The chamois, the steinbock, the Alpine hare, the marmot 

 all migrate when the snow begins to melt, or a little later; they 

 clamber over hillsides and glaciers to the heights above, where the 

 pasturage, now laid .bare, promises rich and abundant nourishment, 

 and they return to the lower slopes of the mountain before winter 

 sets in. The bear, by nature omnivorous, by habit a thief, under- 

 takes a similar migration at the same season, and completes it before 

 winter sets in, — at least so it is in the mountains of Siberia; the 

 various wild cats and dogs which live among the mountains do the 

 same. Such changes of residence occur also on the mountains of 

 southern countries, even of those lying within the tropics. In India 

 and Africa certain species of monkey ascend and descend the moun- 

 tains at regular intervals; elephants seek the high grounds on the 

 approach of summer, the low grounds in winter; on the Andes in 

 South America the guanacos flee before the snow into the valleys, 

 and before the summer-heat to the shoulders of the mountains. All 

 these migrations are confined by the mountains within compara- 

 tively narrow limits. They only involve a change of altitude of 

 from three to nine thousand feet, or a journey which may be 

 accomplished in a few hours, or, at most, in a few days. They have, 

 however, the regularity characteristic of true migrations, especially 

 in the precise periodicity of their occurrence, and not less in the 

 constant choice of the same routes. 



Highlands and plain, sea and air, offer a much wider field than 

 the mountains, and therefore the migrations of the animals inhabit- 

 ing, or temporarily traversing these can be more easily observed, 

 and they are more appropriately termed migratory animals than 

 the dwellers among the mountains. In the tundras of Russia and 

 Siberia, the reindeer, which, in Scandinavia, never leaves the moun- 

 tains, migrates to a great distance every autumn and returns the 

 following spring to his former summer haunts.'^ About the same 

 time it leaves Greenland, and, crossing the sea on a bridge of ice, 

 reaches the continent of America, where it spends the whole winter, 

 only returning to the hills of its native peninsula the following April. 

 In both cases, dread of the approaching winter does not seem to 



