MAMMALS OF MINNESOTA. ae 
_rudder-like tail alone project above the surface, and the long 
V-like diverging ripples which are created by the rapid swim- 
mer soon span the entire stream and stand out in bold relief as 
they catch the sky tints at sunset. In regions not frequented 
by man or sufficiently protected by trees long run ways may 
be traced from these burrows into neighboring meadows or 
wheat fields. The family is large and the appetite is extensive 
if not critical. Almost anything of a vegetable nature will be 
tolerated, but the corn-like roots of rushes and the rhizomes of 
the water lily as well as flag roots are relished. The frantic 
and grotesque haste with which the rat when disturbed rushes 
down the runway toward the water, oblivious to any obstacle, 
is very amusing and sometimes startling, and may have given 
rise to the stories of fierce onslaughts upon man. Young-man- 
afraid-of-his-shadow might readily consider himself beset as 
the excited rat comes crashing down his path regardless of 
everything but his destination. Nevertheless, there seems to 
be considerable evidence that old ‘‘rogue” rats are decidedly 
irascible, and a worried mother rat may overstep the bounds of 
etiquette in defense of her young. The burrowing habits of 
the rat associate him with the cray-fish and other enemies of 
canals and dams. Even in the vicinity of a large city like Cin- 
cinnati large numbers are annually taken in the canal banks 
for their skins, which, when in prime condition, bring 15 to 18 
cents. 
The comparatively simple domicile above described is ade- 
quate for the southern states and flowing waters, but in Wis- 
consin and Minnesota the conditions are very different. Nearly 
every quarter section has its small lake or pond, and these 
pools are shallow and mostly filled with weeds. Here the 
muskrat finds congenial resorts. Even in the bleak prairies 
the sloughs and ponds fairly swarm with these furry denizens. 
Here the intense cold of winter freezes all standing water to a 
depth of over four feet,so that the openings of the summer homes 
of the rat are sealed for four or five months and he is forced to 
construct a building suited to the seeming infelicitous and con- 
flicting conditions. The house must extend above water to ad- 
mit air; it must be deeply buried from the cold; it must connect 
with the water; it must contain food; the food should be grow- 
ing or fresh; the house should afford protection from enemies 
and escape when attacked. 
The solution of these problems might tax the ingenuity of 
the ablest mind, yet nature, by the use of the simplest ma- 
