616 
Hibernating mammals. 
An article on hibernating mammals, by Dr. C. C. 
Abbott, in Science, No. 65, contains several state- 
ments the correctness of which I am inclined to 
challenge. For example: Dr. Abbott says, ‘‘ Of the 
thirty or more mammals found here [central New 
Jersey], thirteen species are supposed to be hibernat- 
ing animals. These are four species of bats, two of 
moles, three squirrels, one ground squirrel, one mar- 
mot, one jumping-mouse, and one Hesperomys.”’ 
If it is true that the red squirrel, ‘two moles,’ 
and ‘one Hesperomys’ hibernate in the latitude of 
central New Jersey, the fact is sufficiently interest- 
ing and important to merit a detailed account of the 
evidence upon which an announcement seemingly 
so extraordinary and improbable is based. 
Further on, the doctor states that the common star- 
nosed moles ‘*‘ form commodious nests, placing a good 
deal of fine grass in them. Here, indifferent to fresh- 
ets, they remain all winter, and, as they can lay up 
no food, sleep, I suppose, through the entire season. 
The fact that these moles are unaffected by being 
submerged during the spring freshets is an interesting 
fact.’’ Here, it will be observed, the author not only 
asserts that the star-nosed moles ‘remain all win- 
ter’ in their nests; but, without adducing a single 
fact in proof, he even goes so far as to assume that 
they are ‘submerged during the spring freshets,’ 
and goes on to say, ‘‘I think that the animals must 
have been thoroughly soaked for from forty-eight to — 
seventy-two hours, the ordinary duration of the high 
water.’’ Now, itis a very easy matter for these semi- 
aquatic animals to betake themselves to higher ground 
when driven from their usual haunts by freshets; 
and this is exactly what usually takes place, as I have 
ascertained by personal observation. 
In the Adirondack region, where snow covers the 
ground for five or six months of the year, the star- 
nosed mole does not hibernate. At the approach of 
winter, it sinks its galleries below the depth to which 
frost penetrates, and still finds an abundance of earth- 
worms, which at all seasons constitute a large share 
of its food. When the snow has attained the depth 
of a metre or a metre and a half, as it commonly does 
here during January and February, the frost gradu- 
ally leaves the ground, and both moles and earth- 
worms again approach the surface. The moles 
sometimes burrow up through the snow; and I have 
captured them while running about on a stiff crust, 
through which they were unable to bore in time to 
make good their escape. 
The red squirrel is well known to be the hardiest 
of his family. Disdaining to hibernate, he remains 
active throughout the continuance of excessive cold. 
When fierce storms sweep over the land, he retires to 
his nest, to re-appear with the first lull in the wind, 
be the temperature never so low. I have frequently 
observed him when the thermometer ranged from 
30° to 40° below zero, Centigrade, but could never see 
that he was troubled by the cold. While running on 
the snow, he often plunges down out of sight, tunnels 
a little distance, and, re-appearing, shakes the snow 
from his head and body, whisks his tail, and skips © 
along as lightly, and with as much apparent pleasure, 
as if returning from a bath in some rippling brook 
during the heat of a summer’s afternoon. 
Dr. Abbott, after commenting upon the fact that 
the jumping-mouse (Zapus Hudsonius) lays up no 
store of provision for winter, while the white-footed 
mouse (Hesperomys leucopus) invariably hoards, says, 
““However this may be, the fact remains that both 
these rodents are quite sensitive to cold, and hiber- 
SCIENCE. 
[Vou. III., No. 68. 
nate as soon as winter sets in; yet how very differ- 
ently is this faculty exercised!”’ eh 
The white-footed mouse is the last animal of which 
I should say, ‘sensitive to cold.’ Like the red 
squirrel, it is one of the hardiest of rodents, and in 
our northern forests it remains active throughout the 
long and severe winters. It is not known to hiber- 
nate; and, except during very stormy weather, its 
footprints can always be seen, dotting the snow in 
various directions. 
If animals that are active in winter throughout the 
north-eastern part of the United States and much of 
British North America should be found hibernating 
in a mild climate like that of central New Jersey, 
the fact would be of unusual interest; but, since its 
acceptance must upset the well-known laws that 
govern the physiological process of hibernation, it 
becomes expedient to sift well the evidence upon 
which such statements rest. OC. HART MERRIAM. 
Experiments with reflections. 
The accompanying figures, though not perfectly 
accurate copies of photographs I have made, are at 
least truthful representations of reflections obtained 
from, 1°, rectilinear striations upon a polished plane; 
2°, circular striations upon a disk; 38°, circular stri- 
ations upon a sphere. 
Fie. 1. 
In fig. 1 the direct rays from a luminous point, a, 
touching the rectilinear striations at b, return to the 
eye a brilliant reflection of the luminous point; 
the divergent rays at c, d, e, f, returning the same with 
decreasing brilliancy as the remoter striations are 
reached. Thus a band of light is reflected perpen- 
dicular to the striations, of uniform transverse diam- 
eter, and with an intenser luminosity at the central 
point. If the striations are upon a finely polished 
surface, the outline of the luminous point is pre- 
served in the reflection quite sharply, whether circu- 
lar or otherwise. 
If the striations are circular and concentric from 
circumference of a disk, —the centre of the disk, 
the light, and the eye oc- 
cupying the same plane, 
and the face of the disk 
perpendicular to it, — the 
reflection is two equal séc- 
tors, with their luminous 
apices united at the centre 
of the disk, as in fig. 2. 
The diameters of the in- 
tercepted arcs depend upon 
the angle formed by the 
incident and_ reflective 
rays. Variations of the 
light, disk, or eye, in posi- 
tion, produce every degree 
of difference between the two sectors. : 
If the striations are upon a polished sphere, and 
