THE BEAVERS OF NORTH AMERICA 33 
that in order to keep the bark perfectly sweet while 
under water for a considerable time, the tree must 
be in a certain condition, otherwise the bark might 
ferment or in some other way become unfit for 
food. The only way in which the beaver can assure 
himself of the tree’s condition is by biting into the 
inner bark, therefore this would account for the 
numerous blazed trees which may be found in the 
vicinity of the ponds and lodges. Carrying this 
idea a little further, we have also a possible ex- 
planation for the fact that such a large number of 
trees are girdled and left often for weeks before 
being finally dropped. This girdling allows the 
tree to dry more quickly than if left with the bark 
on. The acceptance of this theory means, of 
course, that we are endowing the animals with 
extraordinary intelligence ; but how can we avoid 
doing so when we see what they accomplish ? 
When I first described this systematic marking of 
trees, I was ridiculed, partly because it had not 
previously been brought to anyone’s notice (so far 
as I know), but the fact that it is commonly done 
by beavers can be proved by a visit to any place 
where the animals are preparing to store their 
winter food, and as a reason for its being done 
these theories are offered simply as theories. 
It has often been said that cutting down trees is 
the most wonderful work accomplished by beaver, 
but how such a conclusion can be reached is 
difficult to understand. Nearly all of their efforts 
