GROUP BEHAVIOR I5I 



was a reward for cockroaches which, when possible, 

 give a negative reaction to light. 



The three-pronged set of runways was mounted 

 about half an inch above a pan of water, which the 

 majority of the cockroaches tended to avoid, and so 

 kept on the runways. The tests were all made in a 



Fig. 26. A simple maze used in training cockroaches. 



dark room and light was furnished by a single elec- 

 tric bulb mounted just above the point where the 

 central runway left the main platform. In other 

 words, the cockroaches, which are negative to light, 

 had to learn to run through the area of strongest 

 illumination in order to reach the dark bottle which 

 served as a reward. After two minutes' rest in the 

 dark bottle the cockroaches were literally poured out 

 onto the platform of the maze without being touched 

 by the experimenter, and observation of them began 

 again. 



The problem as set was about at the limit of cock- 



