The Republican journal. [volume] (Belfast, Me.) 1829-current, 1912-02-01
THE KITTEN VS.. THE MOUSE.

The most complete piece of expert
mental work bearing upon the subject of
the instructive enmity of cats ard mice
is that of Professor Yerkes and Mr..
Bloomfield. These investigators, work
ing jointly in the Harvard Psychological
Laboratory, made test Of the question,
do kittens instinctively kill mice?"
This question had been answered in the
negative about three years ago by DIR. &.
S. Berry, who worked in the same labor
atory. DR.. Berry reached the conclusion
that leafs are credited with more in
stlncts than they really possess. 1t is
commonly reported that they have an in
stinctive liking for mice, and that mice
have an instructive fear of cats. 1t is
supposed that the odor of a mouse will
arouse cat, and that the odor Of cat
will brighten mouse. My experiments
tend to show that this belief is not in
harmony with the facts. When cats over
five months old were taken into the room
where mice were kept they did not show
the least sign of excitement. A cat would
even allow mouse TO perch upon its
back without attempting to injure it.
Nor did the mice show any fear of the
cats. | have seen mouse smell at the
nose of cat without showing any sign
1f fear. 1t Was not until the ManX
kittens had seen the mother cat catch
and kill the mice AMI had eaten of the
prey, that they learned to DO likewise.
According to DIR. Berry, it is by imita-
ton that the average cat learns to kill
and eat mice.
Professor Yerkes and Mr.. Bloomfield
made much more extensive test upon
the more common varieties of cats. They
worked with eight kittens belonging to
two separate litters. The animals were
brought up by hand and We're kept free
from the influence of older cats. They
tested the kittens with mice much more
often and more Systematically than did
DR.. Berry. When first tested the kittens
were too young and undeveloped to notice
the mice. The instinct was yet 'dor-
mant.' In succeeding tests it became
perfectly clear that as soon as the kit
tens reached the proper age-as soon as
the instinct ripened," as Professor
William James has expressed 1.-THE
congenital mode of response appeared
The authors describe in very clear and
interesting way the behavior of one of
the kittens in one of the tests: mo. Z
was attracted by the movement of the
mouse and touched it with his nose. He
happened to be so placed that he could
see the mouse as it began to move. For
a few seconds he wahtced as if fascinated
by the sight. Then he moved directly and
quickly in spite of the shakinessof his legs
to the mouse and seized it in his mouth by
the middle of the back, at the same time
biting hard and bending his head to the
floor SO that one paw could be placed
firmly on the body of the mouse. In a
few seconds he had killed the mouse.
Without pause the process of eating was
begun" This kitten was only one month
old, and was still weak and shaky in its
movements. The negative results reach
ed by DR.. Berry were possibly due to the
fact that different variety of cat was
used in his experiment; more probable
explanation is that he did not begin his
tests with the animals at young enough
age nor make the tests at frequent enough
intervals. Professor John B. Watson, ir
Harper's Magazine for February.