MAMMALS OF MINNESOTA. 208 
‘domestic cats and other enemies. In such places their nests 
may be found in almost every suitable grass tussock, and under 
fallen trees or driftwood. Such islands are, of course, flooded 
during ashort period in spring, and these freshets are times of 
great excitement among the mice which have domiciled them- 
selves under the boards and riffraff left by the last flood. 
In April, 1885, while in camp upon a large low island at the 
head of lake Pepin, a hard storm of rain and snow caused a 
sudden rise in the river of nearly fifteen inches—sufficient, at 
least, to flood the greater part of the island and float away 
many traps set for mice and shrews in various places. Near 
the tent was a broad bay the low shores of which, for acres in 
extent, were covered with driftwood, which furnished conceal- 
ment for innumerable mice, Arvicola riparius. When the river 
began to rise the water oozed beneath the boards, and before 
the. observer was really aware of the encroachment of the 
waters the whole area was afloat. 
The night was clear and moonlit, and as we stood watching 
the most insidious approach of the waters, wondering if we 
should be compelled to remove our camp, we were astonished 
by a confused rustle and murmur not unlike that produced by 
the wind among dry leaves. This we were at a loss to account 
for since the night was perfectly still. At our feet, however, 
something tangible appeared in the shape of a group of mice 
fleeing from the waters, creeping out from their hiding places, 
in evident alarm, which was expressed in querulous cries as 
well as by their excited and uncertain movements. To use a 
common expression, the whole tract was ‘‘alive’” with mice 
fleeing for their lives toward the higher open ground behind. 
The picture was that of the Ohio fioods, with mice rather than 
men as actors, and furnished an illustration apropos of Burns’s 
lines, ‘‘ The best laid schemes of mice and men gang aft agley.” 
A pair of great-horned owls, whose nest was hard by may have 
profited more by this unexpected hegira than the naturalists of 
the party but, presumably, were less affected by its novelty 
than they. 
Arvicola riparius var. borealis Ricu. 
It is interesting 10 compare a specimen of Arvicola sent us by 
Prof. W.W. Cooke, of Moorhead, Minnesota, with the measure- 
ments and the description of the arctic form called borealis by 
Richardson. This specimen, collected March 15th, 1885, 
