314 THE CANADIAN BEAVER 
a number of “ concepts ” in the beaver’s brain which 
would occur to no other animal. To carry it out 
efficiently would puzzle most human beings not 
acquainted with engineering. Moreover, the work 
must be done with the material at hand, so that 
beaver-dams are found built of branches and mud, 
of grass, of sand, and of mud only. To get the wood 
to the water-side, the beaver clears paths, or “ rolling- 
ways,” cuts a water-channel to meet and assist in 
the transportation of the wood, and in some cases 
actually makes a long canal for water-carriage and 
safe travelling. “Though the beaver-canal is not so 
popularly known,” writes Mr. Martin, “ and is more 
easily reconciled with instinct, it must not be supposed 
that it is a minor feature in the performances of this 
animal ; it is almost incredible that a work, so 
apparently artificial, could have remained unnoticed 
till 1868, when Mr. Morgan published his valuable 
notes, so amply illustrating the works of the American 
beaver. When the colony has been settled quietly 
for many years, and has cut all the desirable trees 
close at hand, and further supplies are sometimes 
hundreds of yards away, the necessity for clear rolling- 
ways and good canals is obvious.” No doubt the 
necessity is obvious, but that does not explain the 
wonder that a small rodent animal should anticipate 
civilized man, and make a road to bring commodities 
to its city, instead of shifting to a fresh encampment 
like the Red Indian himself when supplies are 
exhausted. Our estimate of the individual intelligence 
