taking material for house or dam commonly are 

 turned to useful purpose. The beaver not only 

 builds his mound-like house, but uses the basin 

 thus formed in excavating earthy material for the 

 house for a winter food depository. Ofttimes, too, 

 in building the dam he does it by piling up the 

 material dug from a ditch which runs parallel 

 and close to the dam, and which is useful to 

 him as a deep waterway after the dam is com- 

 pleted. 



In transporting trees for food-supply, water 

 transportation is so much easier and safer than 

 land, that wherever the immediate surroundings 

 of the pond are comparatively level the beaver 

 endeavors to lead water out to tree groves by 

 digging a canal from the edge of the pond to 

 these groves. The felled trees are by this means 

 easily floated into the pond. One of the simplest 

 forms of beaver canal is a narrow, outward exten- 

 sion of the pond. This varies in length from a 

 few yards to one hundred feet or more. 



Another and fairly common form of canal is 

 one that is built across low narrow necks of land 

 which thrust out into large beaver ponds, or on 

 106 



