SOME RESULTS OF EXPERIMENT 149 
To Dr. Thorndike’s monograph we must refer those who 
desire detailed information as to apparatus and procedure. It 
must here suffice to state that the box-cages employed were 
rudely constructed of wooden laths, and formed cramped 
prisons about twenty inches long by fifteen broad and twelve 
high. Nine contained such simple mechanisms as Dr. Thorn- 
dike describes in the passage above quoted. When a loop or 
cord was pulled, a button turned, or a lever depressed, the 
door fell open. In another, pressure on the door as well as 
depression of a thumb-latch was required. In one cage two 
simple acts on the part of the kitten were necessary, pulling a 
cord and pushing aside a piece of board; and in yet others 
three acts were requisite. In those boxes from which escape 
was more difficult a few of the cats failed to get out. The 
times occupied in thoroughly learning the trick of the box by 
those who were successful are plotted in a series of curves, 
the essential feature of which is the graphic expression of a 
gradual diminution in the time interval between imprisonment 
and escape in successive trials. This is shown in Fig. 23, 
which is constructed from some of Dr. Thorndike’s data. In 
some cases the cats were set free from a box when they (1) 
licked themselves or (2) scratched themselves. 
Dr. Thorndike comments on the results of his experiments 
as follows :— 
“When put into the box the cat would show evident signs of dis- 
comfort and of an impulse to escape from confinement. It tries to 
squeeze through any opening; it claws and bites at the bars or wire; 
it thrusts its paws out through any opening, and claws at everything it 
reaches; it continues its efforts when it strikes anything loose and 
shaky: it may claw at things within the box. It does not pay very 
much attention to the food outside, but seems simply to strive in- 
stinctively to escape from confinement. ‘The vigour with which it 
struggles is extraordinary. For eight or ten minutes it will claw, and 
bite, and squeeze incessantly. . . The cat that is clawing all over the 
box in her impulsive struggle will probably claw the string, or loop, or 
button so as to open the door. And gradually all the other non- 
successful impulses will be stamped out, and the particular impulse 
leading to the successful act will be stamped in by the resulting 
