386 C. H. TURNER. 



CONCLUSIONS. 



1 . By means of electric shocks roaches can be trained to avoid 

 entering a specific dark place. This is not a reversal of the photo- 

 tropic responses of the roaches; but the result of learning to avoid 

 a specific dark place because of certain disagreeable experiences 

 associated with it. 



2. Generally speaking male roaches learn more quickly than 

 females and young roaches are more apt than adults; but there 

 are marked individual exceptions to this. 



3. In the ability to learn and to retain what they have acquired 

 roaches exhibit marked individuality. 



4. Roaches that have acquired the habit of refusing to enter 

 a specific dark place do not lose that habit when they moult. 



5. During sickness and just prior to death the retentiveness of 

 the roach is much impaired. 



September 20, 1912. 



