THE BEAVER. 
CaAsTorR FIBER. Linn. 
Amone the numerous, widely dispersed, and_ prolific 
tribes of animals which compose the extremely natural 
Order, called by Linnzus and the writers of his school 
Glires, there are none perhaps which possess so many 
claims on our attention as the well marked and circum- 
scribed little group on the history of which we are 
about to enter. The Beavers in fact interest us not 
only as furnishing a most valuable fur, and as_pro- 
ducing a peculiar secretion occasionally and advan- 
tageously employed in medicine, but also as offering 
the most remarkable of the few instances occurrme 
among quadrupeds, of that architectural instinct, so 
remarkably prevalent in the inferior classes, which 
impels them to construct their own habitations with 
materials selected for the purpose, brought from a 
