SUBSISTENCE OF BEAVERS. 171 



while evergreen trees are the principal forest growth, 

 deciduous tree.'^ are sufficiently abundant for all the 

 purposes of beavei maintenance. There was scarcely 

 any portion of the original forest area of North 

 America, except the exclusively pine tracts, where 

 beavers could not sustain themselves in considerable 

 numbers. Their greatest numbers, however, were 

 found in those particular districts of country where 

 the trees, whose bark was preferred, were found in 

 the greatest profusion. 



The engraving (Plate XV. Fig. 1) is from a photo- 

 graph of an original specimen now in my collection. 

 It was in the process of being cut down by the beavers 

 in October, 1862, when my attention was called to it 

 by some woodmen, who had observed it on the south 

 shore of Lake Flora, near dam No. 2. I went to the 

 place and secured it before the beavers had an oppor- 

 tunity to finish their work, which another night would 

 probably have consummated, to the destruction of the 

 symmetry of the cutting. The tree is a yellow birch, 

 thirteen and a half inches in diameter below the in- 

 cision, and twelve inches above, with a circumference 

 of something over three feet. As the tree was green, 

 and this part was removed before it had been exposed 

 to the weather, the marks of the teeth are seen with 

 entire distinctness over every part of the cut surface. 

 The width of the incision up and down is eight inches, 

 and it was commenced seven inches above the ground. 

 It is evident that the process of cutting is round and 

 round the tree continuously, and that the reduction is 

 uniform until it is cut on all sides more than halfway 

 to the centre. After that, the remainder of the cut- 

 ting varies; in some cases it is uniform until the tree 



