Nankin. When this animal came from China to Japan I shall inquire at a
later opportunity. There were originally in Japan two different species of
mouse, the gray and the white; therefore in order to distinguish our
dancing mouse from these it was necessary to use the name of its native
city.

"In Japan, as in Europe, the animal lives as a house animal in small
cages, but the interest which is taken in it there is shown in quite
another way than in Europe, where the whirling movements, to which the
name dancing mouse is due, are of chief interest. For this reason in
Europe it is given as much room as possible in its cage that it may dance
conveniently. In Japan also the circular movements have been known for a
long time, but this has had no influence upon our interest in the animal,
for the human fashion of dancing with us is quite different from that in
Europe. What has lent interest to the creature for us are its prettiness,
its cleverness in tricks, and its activity. It is liked, therefore, as an
amusement for children. For this purpose it is kept in a small cage,
usually fifteen centimeters square, sometimes in a somewhat broader wooden
box one of whose walls is of wire netting. In this box are built usually a
tower, a tunnel, a bridge, and a wheel. The wheel is rather broad, being
made in the form of a drum and pierced with holes on one side through
which the animal can slip in and out. Running around on the inside, the
mouse moves the wheel often for hours at a time, especially in the
evening. Moreover, there are found in the box other arrangements of
different kinds which may be set in motion by the turning of the wheel. No
space remains in the box in which the animal may move about freely, and
therefore one does not easily or often have an opportunity to observe that
the animal makes circular movements, whether voluntarily or involuntarily.
This is the reason that in its home this interesting little animal has
never been studied by any one in this respect."