W 
86 Mr. Peabody on the 
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living in the milder climates, should be thus defec- 
tive in their power of vision, while the natives 
. of Arctic regions can see both by night and day, 
when the sun or moon shines bright on the snow. 
Without referring to the structure of the eye, it is 
obviously a reason of this difference, that, if those 
birds had not the double power, in latitudes where 
the days and nights are unequal, they would be 
able to see for half the year, and would be blind 
forthe other; and thus, when the days are long, 
must perish for want of food; whereas, to those 
which live where the hours of sunshine are not 
many, even at the summer solstice, it is no hardship 
_ to be compelled to take rest by day. 
Nuttall kept one of these owls in confinement, 
to observe its habits. In the day, it retreated to 
a dark closet ; but as night came on, it grew rest-- 
less, gliding along the room in perfect silence, 4 
power which the owls owe to the delicate plumage 
of their wings. Sometimes it would cling to the 
wainscot, and turn its head almost round, resembling 
a spectre with its bright glaring eyes. In all the 
_ Owls, the globe of the eye is immoveably fixed in 
dts Socket, by an elastic cartilaginous case, in the 
; form of a truncated cone. On removing the out- 
Wal membrane which covers this case, it is found 
to consist of .many parts, placed like the staves 
of a cask, overlapping a little at the narrow end, 
u^ 
and capable apparently of being enlarged or con- . 
ract 
tracted. The eye being thus fixed, the owl, in 
order to see any object, is obliged to turn its head, 
and has the power to move i it round, aiios in a 
imus circle. — we 
M 
ry 
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