38o 



C. H. TURNER. 



to climb up them to freedom. On the other hand, the roaches 

 with amputated antennae move along with a side of the head in 

 contact with one of the side walls of the discrimination box; 

 reminding one very much of a blind person groping along. 

 Usually the movements are rapid, and it requires much punish- 

 ment to cause the roach to avoid the dark chamber. Indeed, 

 the whole behavior of these antennaless roaches impresses one 

 with the thought that the antennae play the same prominent r61e 

 in the behavior of roaches that the eyes do in the behavior of 

 man. Other senses are used, but the antennal sense seems to be 

 the one upon which most reliance is placed. 



a 



f 10 ir *.o j.y 20 



a 



a 



f 10 If 20 15~ 30 



B 



10 



If 3.0 



30 35 



FIG. 2. Reaction curves of three adult females. The numbers represent 

 opportunities to make a choice; a represents refusals to enter the dark chamber, 

 b represents entrances into the dark chamber. 



I stated above that male roaches are more apt than females 

 and that young roaches are more apt than adults. Restricted to 

 the average of each group this assertion is true; but, when we 

 consider individuals as such, we can make no such universal 

 statement. I have encountered males (Fig. 3, E) that were 

 much slower to learn than dull females (Fig. 2, A) and I have seen 

 larval females that were less apt (Fig. 4, B ; Fig. 4, D) than adult 



