ing poor eyesight are bats, black bears 
and mule deer. The expression “blind 
as a bat” is one that is commonplace, 
proverbial and, if not strictly true, has 
at least the merit of being based on 
fact. 
Fo8: like the mole, this animal has 
been furnished with eyes, but they 
are small, weak and restricted in range 
to a narrow radius. This seems a 
rather anomalous circumstance when 
one considers that many bats live en- 
tirely on insects which they capture in. 
mid-air and at an hour when daylight 
is merging into dark and when visibil- 
ity is low. Recent experiments carried 
out with live bats would almost indi- 
cate that these winged animals are 
possessed of a mysterious sense akin 
to that of touch and one which is as 
yet beyond the bounds of human knowl- 
edge. 
When black bear cubs are born they 
are naked and blind. Indeed so poorly 
developed are they that a period of 
forty days elapses ere they gain sight. 
And even when these bears have grown 
to great size and to maturity, their 
eyesight is far from being good. While 
not exactly short sighted in the strict 
sense of the word, yet they appear to 
be unable to discern familiar objects at 
comparatively short range. Moving 
about in their usual habitat, particu- 
larly in places where the underwoods 
are dense, bears of this species are ac- 
customed to stand erect at intervals the 
better to survey their surroundings. At 
such times they peer anxiously, per- 
plexedly, and as if conscious of an un- 
seen enemy. The eye socket of the 
black bear forms a complete circle of 
bone; that of the grizzly bear a half 
circle only. 
Mule Deer are notoriously deficient 
in eyepower. Although able to scent 
a man at a distance of over a mile, yet 
their vision is so restricted that they 
cannot see clearly beyond a distance of 
fifty feet. During the past twenty 
years the writer has had ample op- 
portunity to test the sight of many 
deer of this species. During the winter 
months large numbers of them come to 
the cabin door in search of food. Raw 
potatoes are eagerly sought by these 
hungry vagrants. If a few small tu- 
bers be thrown upon the bare ground 
and that when the deer are distant but 
a few yards, they will almost be com- 
pelled to resort to sense of smell in 
order to locate the elusive “spuds.” 
RAGMENTS of proffered food, 
scattered upon the snow, are actu- 
ally probed for by the wild deer which 
are our guests over a greater part of 
the year. When the ground is covered 
with snow and the sun shines brightly, 
the light is trying to the eyes of most 

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developed, but his sight is poor. 
creatures. At such times the pupil in 
a mule deer’s eye is contracted to a 
horizontal slit about one inch long by 
one-eighth inch wide. 
Many of the forms of life which we 
refer to as “lowly” possess visual or- 
gans that are strikingly curious. Thus 
the eyes of the slug are placed on the 
tips of the feelers which protrude from 
the head. When not in use these minia- 
ture periscopes are withdrawn into the 
body so that the eyes may be effectu- 
ally shielded from harm. Water snails 
have the eyes placed at the base of the 
tentacles. Cyclops, the mythological 
one-eyed god, has a present-day name- 
sake in the shape of a fresh water 
crustacean, this creature being pro- 
vided with but one eye. Lobsters have 
a wide field of vision, the eyes being 
placed on short tentacles. The clam 
has no eyes. A few spots on the edge 
of the mantle of this mollusk are 
thought to be sensitive to the action of 
light, but this has so far proved largely 
speculative. 
NAKES have at all times an omi- 
nous stony stare occasioned by the 
entire absence of eyelids. The lens in 
the eye of a fish forms an almost per- 
fect sphere, that in most land animals 
being slightly flattened. Insects are 
(Continued on page 690) 
651 
