INTEGRATION OF MOVEMENTS IN LEARNING IN THE RAT 431 



TABLE 4 Continued 



second, but no gradual decrease in the performance of this move- 

 ment occurred. No remarks need be made of the total time 

 required to solve the problem, for variations in them can be 

 accounted for in the variations that appear in the reaction time 

 for directive integration and for the neck reflex movement. The 

 number of reaction times taken with this rat was 78, and no 

 imperfect responses occurred throughout the trials. In order 

 that the results obtained from this rat may appear more uni- 

 form with the remaining tables given, only the reaction times for 

 55 trials are presented. The records of the 23 trials which are 

 omitted did not vary from the last 15 of the 55 trials. 



The records of the rats presented in the other tables are quite 

 different from the preceeding one. They are from rats whose 

 reflex thrusts are functionally poorly developed, fluctuating at 

 shorter or longer intervals. Tables 5, 6, and 7, are from rats 

 whose reflex thrusts appear from the very first trial poorly de- 

 veloped; tables 8 and 9 are records of rats whose reflex thrusts 

 fluctuated often and greatly. The records of these two groups 

 of rats present different results. The rats of the first group pos- 

 sessed in the first or second trial an ipsilateral fore reflex thrust, 

 when the head was passively bent to one side, usually none when 

 the head was dorsally extended 45 degrees of the midline of the 

 body, and weak or absent hind reflex thrusts when the tail was 



