1 Nov 23 130" 14 100" 8 170" 13 60" 6 190" 26 130" 13.4
2 24 140 19 78 7 60 8 149 6 211 25 128 13.0
3 25 392 31 87 1 98 5 185 13 120 9 176 11.8
4 26 448 38 38 3 47 2 50 3 121 12 141 11.3
5 27 142 8 21 2 27 3 27 2 17 1 47 3.2
6 28 45 2 61 7 63 5 102 8 33 4 61 5.2
7 29 303 17 64 7 36 3 42 2 57 4 100 6.6
8 30 222 15 26 2 37 5 42 3 7 0 67 5.0
9 Dec 1 185 9 36 5 48 3 63 3 94 8 85 5.6
10 2 52 2 71 4 19 0 196 5 95 11 87 4.4
11 3 180 8 32 2 107 4 52 3 38 4 82 4.2
12 4 310 10 133 11 65 3 242 6 125 6 175 7.2
13 4 153 9 335 55 130 10 195 15 154 18 193 21.4
14 5 330 7 69 2 42 2 201 6 130 10 154 5.4
15 5 287 7 34 4 61 4 136 7 25 2 109 4.8
16 5 455 15 65 4 25 0 110 8 160 15 183 8.4
17 6 120 15 280 9 33 0 168 4 39 2 128 6.0
18 6 120 4 164 10 81 4 101 5 85 4 110 5.4
19 6 132 12 78 7 110 6 40 2 151 12 102 7.8
20 7 258 10 223 16 33 1 92 5 37 1 129 6.6
21 7 110 7 23 3 44 4 20 4 305 23 100 8.2
22 7 100 4 60 8 167 15 44 7 58 4 86 7.6
23 8 43 1 179 7 356 6 34 3 65 3 135 4.0
24 8 92 5 56 5 42 3 17 1 23 1 46 3.0
25 9 85 5 114 3 62 3 129 8 31 0 84 3.8
26 9 30 2 36 4 109 15 12 1 34 2 44 4.8
27 9 69 5 40 4 85 6 36 3 16 1 49 3.8
28 10 169 7 80 3 28 0 142 5 35 2 89 3.4
29 10 155 5 266 8 91 5 27 0 37 2 115 4.0
30 10 29 1 25 2 124 14 83 6 111 12 74 7.0
31 10 465 6 208 8 95 3 65 3 159 13 198 6.6
On the basis of two tests per day, two common mice, a white one and a gray one, quickly learned to escape from labyrinth A by the shortest path. The time of escape for the gray individual (Table 37) decreased from 180" in the first test to 21" in the tenth, and the number of errors from 6 to 1. Similarly in the case of the white individual, the time decreased from 122" to 8", and the errors from 5 to 1. A fraction of the number of tests to which the dancer had been subjected sufficed to establish a habit of escape in the common mouse. It is evident, therefore, that the dancer differs radically from the common mouse in its behavior in a maze, and it is also clear that the labyrinth method, if it is to be used to advantage, must be adapted to the motor tendencies of the animal which is to be tested.
TABLE 37
RESULTS OF LABYRINTH A TESTS WITH COMMON MICE
GREY MOUSE WHITE MOUSE TEST T E T E
1 180" 6 122" 5
2 26 2 80 6
3 37 1 56 4
4 18 0 27 1
5 68 2 33 2
6 10 1 19 1
7 11 1 17 1
8 13 1 17 1
9 10 0 8 1
10 21 1 8 1
The behavior of the dancer made obvious two defects in labyrinth A. Its passages are so large that the mouse is constantly tempted to dance, and it lacks the basis for a strong and constant motive of escape by the direct path. To obviate these shortcomings labyrinth B was constructed, as is shown in Figures 23 and 24, with very narrow passages, and a floor which was covered with the wires of an interrupted electric circuit so that errors might be punished. The length of this labyrinth was 52 cm. and the passages were 2.5 cm. wide and 10 cm. deep. Dancing in these narrow alleys was practically impossible, for the mice could barely turn around in them. In the case of all except the common mice and two dancers, a depth of 10 cm. was sufficient to keep the animals in the maze without the use of a cover.
As an account of the behavior of the dancer in labyrinth B has already been given in Chapter XI, I may now state the general results of the experiments. In all, thirty individuals were trained in this labyrinth. Each individual was given tests at the rate of one per minute until it had succeeded in following the correct path five times in succession. The weak electric shock, which was given as a punishment for mistakes, provided an activity-impelling motive for escape to the nest-box.
An idea of the extreme individual difference in the rapidity with which the labyrinth-B path was learned by these dancers may be obtained by an examination of Table 38, from which it appears that the smallest number of training tests necessary for a successful or errorless trip through the maze was one and the largest number fourteen. It is to be remembered that each mouse was given an opportunity to pass through the labyrinth once without punishment for errors, and thus to discover, before the training tests were begun, that a way of escape existed. This first test we may designate as the preliminary trial. Table 38 further indicates that the females acquired the labyrinth habit more quickly than did the males.