CONSTRUCTING A BEAVER DAM 
greens; but the bulbous roots of lilies and other aquatic plants are also 
well liked. 
A beaver colony begins with the settlement upon some wood- 
land water, in midsummer, of a pair of young immigrants. 
Their first work is to dig a burrow in the bank, pame and 
entered from beneath the water. This done, two Lodges. 
conditions are needful to maintaining the homestead: one is 
that there must remain enough water in front of the burrow 
to cover the entrance, and bar out such enemies as wild cats and 
foxes, and the other, that the water must be too deep to freeze 
After Morgan. 
MAP OF THE GREAL BEAVER DAM AT GRASS LAKE, MINN., IN 1830, 
tothe bottom. As the lowering waste of late summer admonishes 
them of danger in these directions, the beavers choose a point 
in their stream where the bottom is firm, and begin to make a 
dam high and strong enough to hold back the water at a proper 
height throughout the winter. 
They start by cutting saplings leafy at the top, and dragging or float- 
ing them to the place. The current straightens these out, with the brushy 
tips downstream, and they are forced to the bottom and made to lie there 
by having stones and mud heaped upon them; it is astonishing what large 
stones the animals are able to roll and push into this service. This work 
is performed mainly at night, each animal doing what he thinks proper. 
The fine old stories of a’ superintendent who sets tasks, are as fanciful and 
463 
