The dancing or waltzing mouse is a Japanese variety with many
peculiarities, such as having only one of the three semicircular canals
of the ear well developed. It has a strong tendency to waltz round and
round in circles without sufficient cause and to trip sideways towards
its dormitory instead of proceeding in the orthodox head-on fashion. But
this freak is a very educable creature, as Professor Yerkes has shown.
In a careful way he confronted his mouse-pupil with alternative pathways
marked by different degrees of illumination, or by different colours. If
the mouse chose compartment A, it found a clear passage direct to its
nest; if it chose compartment B, it was punished by a mild electric
shock and it had to take a roundabout road home. Needless to say, the A
compartment was sometimes to the right hand, sometimes to the left, else
mere position would have been a guide. The experiments showed that the
dancing mice learn to discriminate the right path from the wrong, and
similar results have been got from other mammals, such as rats and
squirrels. There is no proof of learning by ideas, but there is proof of
learning by experience. And the same must be true in wild life.
Many mammals, such as cats and rats, learn how to manipulate
puzzle-boxes and how to get at the treasure at the heart of a Hampton
Court maze. Some of the puzzle-boxes, with a reward of food inside, are
quite difficult, for the various bolts and bars have to be dealt with in
a particular order, and yet many mammals master the problem. What is
plain is that they gradually eliminate useless movements, that they make
fewer and fewer mistakes, that they eventually succeed, and that they
register the solution within themselves so that it remains with them for
a time. It looks a little like the behaviour of a man who learns a game
of skill without thinking. It is a learning by experience, not by ideas
or reflection. Thus it is very difficult to suppose that a rat or a cat
could form any idea or even picture of the Hampton Court maze--which
they nevertheless master.