CASTOR FIBER. 



branches of trees they intermingle mud and stones to give 

 greater security, and when dams have been long undisturbed 

 and frequently repaired, they acquire great solidity, and their 

 power of resisting the pressure of water and ice is greatly 

 increased by the willow, birch, &c. occasionally taking root, 

 and eventually growing up into something of a regular hedge. 

 The materials used in constructing the dams are secured 

 solely by the resting of the branches, &c. against the bottom, 

 and the subsequent accumulation of mud and stones by the 

 force of the stream or by the industry of the beavers. In 

 various parts of the Western country, where beavers are at 

 present entirely unknown, except by tradition, the dams con- 

 structed by their labors are still standing securely, and in 

 some instances serve instead of bridges to the streams they 

 obstruct. There are few States in the Union in which some 

 remembrance of this animal is not preserved by such names 

 as Beaver-dam, Beaver-lake, Beaver-falls, &c. 



The dwellings of the beaver are formed of the same mate- 

 rials as their dams, and are very rude, though strong, and 

 adapted in size to the number of their inhabitants. When 

 building their habitations, they place most of the wood cross- 

 wise, and nearly horizontally, observing no other order than, 

 that of leaving a cavity in the middle. Branches which pro- 

 ject inward are cut off with their teeth and thrown among 

 the rest. The places are by no means built of sticks first, 

 and then plastered, but all the materials, sticks, mud, and 

 stones, if the latter can be procured, are mixed up together, 

 and this composition is employed from the foundation to the 

 summit. The mud is obtained from the adjacent banks or 

 bottom of the stream or pond near the door of the hut. Mud 

 and stones the beaver always carries by holding them be- 

 tween his fore paws and throat. Their work is all performed 

 at night, and with much expedition. When straw or grass 

 is mingled with the mud used by them in building, it is an 

 accidental circumstance, owing to the nature of the spot 

 whence the latter was taken. As soon as any part of the 

 material is placed where it is intended to remain, they turn 

 round and give it a smart blow with the tail. The habit 

 of flapping with the tail is retained by then* in a state of 

 captivity, and, unless it be in the acts already mentioned, ap- 

 pears designed to effect no particular purpose. Their dwell- 

 ings which have stood for some time, and been kept in repair, 



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