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C. H. TURNER. 



been rounded to prevent scratching. Accurate records were kept 

 of the behavior of each roach and of the number of shocks given. 

 Whenever a roach made ten successive refusals to enter the dark 

 chamber the experiment was terminated for that time. Except 

 where I was testing the result of intervals of less than a day, the 

 experiments were conducted at about the same time each day. 

 Some of the results of these experiments are recorded in the 

 accompanying tables. Although the records of all of the experi- 

 ments performed have not been tabulated, yet the selected experi- 

 ments exhibit all of the types of behavior observed. The Arabic 

 numerals in the narrow vertical columns indicate the number of 

 shocks necessary to cause the individual to make the number of 

 successive refusals to enter the dark chamber that is indicated 

 by the Roman numeral in the column to the extreme left. Each 

 shock represents an error made by the roach. For the sake of 



TABLE V. 





SHOWING THE ABILITY OF ADULT FEMALES WITH AMPUTATED ANTENNAE TO 

 LEARN TO AVOID ENTERING A SPECIFIC DARK PLACE. 



