178 THE AMERICAN BEAVER. 



trees, one of which, nearly three feet in diameter, had 

 been gnawed through by them."^ After passing Fort 

 Randall, in ascending the Missouri, the cottonwood- 

 tree cuttings are seen in places in great numbers 

 along a distance of a thousand or more miles to the 

 mountains. At some points, as elsewhere stated, they 

 are cut down in such quantities as to form piles of 

 timber; but where these occur, the trees are usually 

 small. On the Yellowstone River, where the quan- 

 tity of cotton-wood is small and confined to the bottom 

 lands, the be:ivers were making such havoc at the 

 time of my visit (1862) that the Crow Indians had 

 become seriously concerned about their own supply of 

 wood. This may seem extravagant, and it probably 

 was an unnecessary alarm : but it is also easy to dis- 

 cover that with beavers very numerous and the sup- 

 ply of wood limited, they might draw overlargely 

 upon the supply. 



Small trees and the limbs of large trees are cut 

 into pieces of convenient length for transportation, 

 and consequently must bear a definite relation to the 

 physical powers of the animal. It is necessary to 

 move them on land, from where they are cut, to the 

 nearest accessible point in the pond, whence they 

 are floated to the place where they are to be sunk 

 to form a magazine of provisions for the winter. 

 The larger, therefore, the limb is in diameter, the 

 shorter must be the cutting in order to be movable. 

 A comparison of a large number of these cuttings 

 shows that when five inches in diameter, they are 

 usually about a foot long; when four inches in diam- 



^ Travels, etc. Longman's ed., p. 146. 



