S68 ANIMAL INTELLIGENCE. 



overstocked, some of the beavers migrate. The Indians 

 say that in their local migrations the old beavers go up 

 stream, and the young down ; assigning as a reason that 

 in the struggle for existence greater advantages are 

 afforded near the source than lower down a stream, and 

 therefore that the old beavers appropriate the former. 

 But although lodges may thus be vacated by the old 

 beavers, they are not left tenantless ; their lease is, as it 

 were, transferred to another beaver couple. This process 

 of transference of ownership goes on from generation to 

 generation, so that the same lodges are continuously 

 occupied for centuries. 



These lodges, which are always constructed in or near 

 water, are of three kinds — the island, bank, and lake 

 lodge. The first are formed on small islands which may 

 happen to occur in the ponds made by the beaver-dams. 

 The floor of the lodge is a few inches above the level of 

 the water, and into it there open two, or sometimes more 

 entrances : — 



These are made with great skill, and in the most artistic 

 manner. One is straight, or as nearly so as possible, with its 

 floor, which is of course under water, an inclined plane, rising 

 gradually from the bottom of the pond into the chamber; while 

 the other is abrupt in its descent, and often sinuous in its 

 course. The first we shall call the ' wood entrance,' from its 

 evident design to facilitate the admission into the chamber of 

 their wood cuttings, upon which they subsist during the season 

 of winter. These cuttings, as will elsewhere be shown, are of 

 such size and length that such an entrance is absolutely neces- 

 sary for their free admission into the lodge. The other, which 

 we shall call the 'beaver entrance,' is the ordinary run- way 

 for their exit and return. It is usually abrupt, and often wind- 

 ing. In the lodge under consideration, the wood entrance de- 

 scended from the outer run of the chamber entrance about ten 

 feet to the bottom of the pond in a straight line, and upon an 

 inclined plane ; while the other, emerging from the line of the 

 chamber at the side, descended quite abruptly to the bottom of 

 the moat or trench, through which the beavers must pass, in 

 open water, out into the pond. Both entrances were rudely 

 arched, with a roof of interlaced sticks filled in with mud in- 

 termixed with vegetable fibre, and were extended to the bottom 



