348 WALTER S. HUNTER 



mittent noise of about 150 interruptions per minute. The ex- 

 perimenter had been using handclaps for a noise stimulus for 

 many months and had reduced the clapping to an automatism 

 which varied but slightly in rate. 



The following are the controls used in the analysis of the two 

 habits described. (In the formation of the habits, punishment 

 and reward were used. In the controls, punishment was never 

 used for fear of breaking up the association.) 



K = turn right for h.c. and left for buzzer. 



h.c. = turn right for h.c. and left for silence. 



B = turn left for buzzer and right for silence. 



Control 1. Hissing through the teeth, turn left. 



Control 2. Hissing through teeth, turn right. 



Control 3. "Rush of air" sound with lips, turn right. 



Control 4. "Rush of air" sound with lips, turn left. 



Control 5. Buzzer sounded for two seconds, at intervals of one sec- 

 ond, turn left. 



Control 6. Buzzer sounded normally, turn right. 



Control 7. Metronome beating 120 per minute, turn right. 



Control 8. Metronome beating 120 per minute, turn left. 



Control 9. Metronome beating 200 per minute, turn right. 



Control 10. Metronome beating 200 per minute, turn left. 



Control 11. Metronome beating 160 per minute, turn right. 



Control 12. Metronome beating 176 per minute, turn right. 



Control 13. Motor knocking 180 per minute, turn right. 



Control 14. Motor knocking 232 per minute, turn left. 



Control 15. Motor knocking 140 per minute, turn left. 



Control 16. Motor knocking 240 per minute, turn right. 



Control 17. Motor knocking 250 per minute, turn left. 



Control 18. Motor knocking 500 per minute, turn left. 



Control 19. Beats 120 per minute with 512 v.s. forks, turn right. 



Control 20. Beats 142 per minute with 512 v.s. forks, turn right. 



Control 21. Beats 174 per minute with 512 v.s. forks, turn right. 



Control 22. Beats 3840 per minute with 512 v.s. and 576 v.s. forks, 

 turn left. 



Not all of these controls could be used with each rat, and the 

 limitations of time prevented their being exhaustively applied. 

 The buzzer used was an ordinary commercial one and was sus- 



