Year: 1872




Mr.. d. y Spaidin., ia paper read be-
fore the British Association at its last


meeting. and printed iu Nature, gave the
/ result Of some very interesting expert
meuts which he has been making with "a
I view 10 sowing the question whether the
+ power OF animals 10 estimate distance and
/ perceive direction by means OF sight aud
nearing Is really an distinctive one. or Is.
AS some hold only the result OF rap d
I learning from experience and imitation.
4 Against the Instructive character OF these
perceptions 1t Is argued that as distance
means movement, locUmotion, the very
/ essence Of the idea is such as cannot be
taken IN by the eye or ear that what
the varying sensations OF sight and hear
ing correspond t0. must be got at by
moving over the ground by experience.
The results. however, OF experiments on
chickens were wholly in favor OF the in-
stinctlve nature OF these perceptions
! Chickens kept in a state of blindness by
various devices, from one to three days.
when placed IN the light under set of
carefully prepared conditions, gave cou-
elusive evidence against the theory that
the perceptions Of distance and direction
/ by the eye are the result OF associations
| formed in the experience of each individ-
ual life. Often, at the end Of two minutes,
they followed with their eyes the move
ments Of crawling insects, turning their
heads with all the precision of an Old fowl.
In from two to fifteen minutes they peck
ed at some object, showing not merely an
instructive perception Of distance, but an
original ability to measure distance with
something like intallible accuracy. If be-
yond the reach of their necks, they
walked or run up to the object Of their
pursuit, and may be said to have invari
ably struck it, never missing by more than
a hairs-breadth this, too, when the
specks at which they struck were no big
ger than the smallest visible dot of an {.
To seize between the points Of the mandible
at the very instant Of striking seems a
more difficult operation Though at times
they seized and swallowed an insect at the
first attempt, more frequently thev struck
five or six times, lifting once or twice be-
fore they succeeded in swallowing their
first food. To take, by way of iliustra-
ton, the observations on a single case a
little in detail A chicken at the end of
six minutes, after having its eyes unveiled,
followed with its head the movements of
fly twelve inches distant at ten minutes,
the fly coming within reach of its neck.
was seized and swallowed at the first
stroke; at the end Of twenty minutes it
had not attempted TO walk step. 1t was
then placed on the rough ground within
sight and call Of hen, with chickens of
its own age. After standing chirping for
about minute, it went straight towards
the hen, displaying as keen perception of
the outer world as it was ever likely to
possess in after life. 1t never required to
knock its head against a stone to discover /
that there was no road that way" 1t /
leaped over the smaller articles tsat Law in .
It's path, and ran round the larger, reach
ing the mother IN as nearly straight line /
as the nature of the ground would permit. |
Thus 1t would seem that, prior to expert
ence, the eye-at least the eyeof tie chick