By means of the discrimination method previously used
in the preliminary experiments on color vision, a
full description of which may be found in Chapter
IX, p. 133, the dancers’ ability to perceive
form was tested. Immediately after the two males
A and B had been given the “food-box”
tests, whose results appear in Table 15, they were
tested in the same apparatus and by the same method
for their ability to discriminate a rectangular food-box
from a round one. In the case of the color discrimination
tests, it will be remembered that the circular tin
boxes 5 cm. in diameter by 1.5 cm. in depth, one of
which was covered with blue paper, the other with
orange, were used. For the form discrimination
tests I used instead one of the circular boxes of
the dimensions given above and a rectangular box 8.5
cm. long, 5.5 cm. wide and 2.5 cm. deep. “Force”
was placed in the circular box. The tests were
given, in series of 20, daily.
VISUAL FORM TESTS
SERIES DATE MOUSE A MOUSE
B
RIGHT
WRONG RIGHT WRONG
(CIRCULAR
(RECTANGU- (CIRCULAR (RECTANGU-
BOX)
LAR BOX) BOX) LAR BOX)
1 Jan. 5 10 10
9 11
2 7 12
8 13 7
3 10 6 14
10 10
4 11 7 13
10 10
5 12 9 11
10 10
6 13 11
9 11 9
7 14 13
7 9 11
8 15 10 10
11 9
9 16 10 10
11 9
10 17 11 9
9 11
11 18 11 9
12 8
12 19 12 8
10 10
13 20 10 10
12 8
14 21 10 10
8 12
15 22 10 10
10 10
Totals 152
148 155 145
The results of 15 series of these tests, as may be
seen by the examination of Table 30, are about as
definitely negative, so far as form discrimination
is in question, as they possibly could be. From
the first series to the last there is not one which
justifies the inference that either of the dancers
depended upon the form of the boxes in making its
choice. In view of the general criticisms I have
made concerning the use of hunger as a motive in experiments
on animal behavior, and in view of the particular
criticisms of this very method of testing the discriminating
powers of the mouse, it may seem strange that space
