n an unsuspecting
fellow-cat-baby's back, just as they will do later in life, when seeking
their prey. I have seen them play with a catnip mouse for hours at a
time, just as the mother cat plays with a real mouse.

Brehm says that this is noticed in their earliest kittenhood, and that
the mother cat encourages it in all ways possible, even to becoming a
child with her children from love of them, as a human mother does in the
nursery with her child. The mother cat begins the play by slowly moving
her tail. Gesner considered her tail as the indicator of her moods. The
kittens, while they may not understand what this means, are greatly
excited by the movement, their eyes sparkle, their ears stand erect, and
slowly one after another clutches after the moving tail. Suddenly,
one springs over the mother's back, another grabs at her feet, while a
third playfully slaps her in the face with his tiny, soft, cushioned
paw. She, patiently and mother-like, lovingly submits to all this
treatment, as it is only play.

[Illustration: _American Museum of Natural History, New York_

DRYPTOSAURUS. THE PREHISTORIC ANIMALS, TOO, UNDOUBTEDLY HAD THEIR PLAY
TIME, WITH GAMES AND "SETTING UP" EXERCISES.]

[Illustration: _American Museum of Natural History, New York_

A HAPPY FAMILY OF POLAR BEARS. THE YOUNG CUBS WRESTLE AND TUMBLE, AS
PLAYFULLY AS TWO PUPPIES. THIS PLAY HAS MUCH TO DO WITH THEIR PHYSICAL
AND MENTAL DEVELOPMENT.]

Many scientists have claimed that this so-called instinct should not be
classed as real play. However, such an authority as Darwin thought it
was play, and Scheitlin said that the cat let the mouse loose many times
in order that she might have the experience of catching it each time. No
mercy is shown the helpless mouse, which is the same to her as the toy
ball--in the same way as a real beetle and a toy beetle are the same to
a small child. Evidently the cat does not play with the mouse for the
delight in torturing it, but purely for practice that she may become
skilled in the art of catching it. The cat also exercises in springing
movements, and by studying the mouse's probable movements, learns to
acquire a knowledge and skill in mouse-ways otherwise impossible.

The same cruel practice is found among leopards, panthers, and wild
cats. Brehm verifies the observation that many members of the cat family
practise torturing their victims in a horrible manner, pretending to
liberate them, until the poor creatures