30 THE AMERICAN BEAVER. 



extent than upon his sight. He sits up on his hind 

 legs to listen, which is his usual position when on the 

 alert or suspicious of clanger. He will often select a 

 slightly elevated and exposed position, and, sitting up, 

 listen for a considerable time and then retire, but to 

 return at intervals and repeat the observation until 

 satisfied whether or not danger is near. Since this 

 attitude is one expressive of intelligence, as well as 

 the one in which his form is seen at the best advant- 

 age, I have adopted it in the engraving (Plate I.) as 

 the most suitable for his representation. 



Scarcely inferior to this sense in power is that of 

 smell, which is abundantly attested by the structure 

 of the nasal organs. The cavity occupied by the eth- 

 moid and turbinated bones is but little inferior in size 

 to that in which the brain is enveloped. As these 

 bones are laminated, the superficial surface of mem- 

 brane exposed to the air is very large. It is evident 

 from structural considerations that smell and hearing 

 are the principal informing senses of the beaver. 



Their social propensities furnish another character- 

 istic. They pair, and with their offspring live in the 

 family relations until the latter attain maturity, when 

 they are forced to leave the parent lodge. It usually 

 happens that two or more such families inhabit the 

 same pond, and contribute their labor to the mainte- 

 nance of the dam, whence the common and nearly 

 universal opinion that they live and act in colonies, 

 or associated in villages. This is altogether an over- 

 statement. Each family has its own lodge and bur- 

 rows, and its separate stock of winter provisions ; and 

 there is no authentic evidence of any concert of ac- 

 tion among several families, either in building or 



