May 2, 1884. | 
not seem affected by a mere succession of hard 
frosts. As insect-life is not materially affected 
by the first few frosts, there does not seem 
any reason for their withdrawal from active 
life, and therefore it is not surprising that even 
up to Christmas, bats should be seen flying, at 
sunset, in considerable numbers. When the 
steady cold of an average winter fairly reaches 
us, bats hibernate in two ways. If they re- 
sort to the ordinary shelter of a hollow tree, 
or similar locality, that is considerably exposed 
to the wind, then many individuals cluster to- 
SCIENCE. 
539 
flues which passed through it, and which were 
in constant use during the time. ‘This bat 
could be taken down and hung up as readily 
as an inanimate object, yet clearly showed that 
it was conscious of the disturbance to which it 
was subjected. Once I brought it into a warm 
room, when it revived in thirty minutes, and 
flew about the apartment, but not with a very 
steady, well-directed flight. When taken again 
to the attic, it responded to the effects of the 
lower temperature by resuming its former po- 
sition, after a steady to and fro flight from end 
THE DUSKY BAT, VESPERTILIO FUSCUS (ONE-HALF NATURAL SIZE). 
gether ; and contact is mutually beneficial, for 
the torpor of hibernation is not rapidly, but 
rather gradually acquired. Such clusters of 
bats, if disturbed immediately after gathering 
together, are as resentful as when captured 
during midsummer ; and not until three or four 
days have elapsed do they become insensible 
to disturbance. If this be very violent, and 
the creatures roused suddenly, a curious con- 
dition of aimless activity ensues, but lasts for 
a short time only, and often ends in death. 
On the other hand, I have very frequently 
found solitary bats in curiously out of the way 
places, where they were so protected that they 
could not have suffered from the severity of 
the season, however intense. In such cases the 
torpor was never profound, the temperature 
of the body but little reduced, and the heart’s 
action almost normal. For instance: a single 
dusky bat (Vespertilio fuscus) slept, or hiber- 
nated, as described, for thirteen weeks, in the 
attic of my house. It clung to a nail driven 
into the wall of the chimney, and was protect- 
ed by a piece of woollen cloth hanging from a 
beam above it. The chimney retained a little 
of the warmth derived from the three smoke- 
to end of the attic for nearly an hour. ‘The 
bat seemed to be wholly aware of the position 
of the nail in the chimney, and, when wearied 
of its flight, turned to it directly, and, fold- 
ing its wings about it, seized the nail with a 
tighter grip, and hung, head down, as it had 
been doing. In two hours I went to it again, 
and found it as indifferent to handling as be- 
fore. 
The two species of moles so common with 
us hibernate in quite different ways, the habit 
varying as much with them as does the char- 
acter of their respective habitats. 
The common mole (Scalops aquaticus) — 
which, by the way, is in no sense aquatic — bur- 
rows deeply into dry soils, keeping just beyond 
the frost-line ; and there it remains, without a 
nest of any kind, until the warmth of the spring 
sunshine melts the frost, loosens the soil, and 
sets the subterranean prisoner free. If, as 
sometimes happens, the cold is unusually in- 
tense and sudden, the ground freezes below 
the resting-places of the hibernating moles, 
and then they are frozen to death. ‘This, I 
judge, does not often occur ; but the approach- 
ing frost rouses them sufficiently to place them 
