282 



J. F. SHEPARD AND F. S. BREED 



average accuracy score of 36 and 37 respectively on the regular 

 scale of 50. The data are given in table 2. 



TABLE 2 



Rate of Improvement During the First Twenty-four Hours After 

 Five Days' Artificial Delay, Groups V x and V 2 



A critic may interpose at this point that the chicks, upon 

 being given their natural freedom after the first tests, improved 

 as they did because they made up lost practice in excessive 

 pecking. Careful observation of the animals did not attest this 

 view. Furthermore, there are two valid objections to this 

 objection: (1) Practice was necessarily limited by the food 

 allowance, and (2) practice was also limited by the food capac- 

 ity of the animals. 



An answer to one more possible objection. One of the writers 

 found in previous experiments that chicks peck at and eat food 

 when light is excluded. On the basis of this fact it may be sup- 

 posed that dark-room conditions do not prevent the pecking 

 response and therefore practice. It should be noted, however, 

 that, in the earlier experiments referred to, all the animals had 

 practiced previously in the light. No evidence of pecking was 

 found while groups I to V were in the dark-room. These chicks 

 did not even peck for food while being artificially fed. 



CRITICISM OF SPALDING 



The accuracy of the first pecking reactions after artificial 

 delay has surely been much exaggerated by Spalding. It will 

 be recalled that Spalding employed a hooding device to prevent 

 practice for from one to three days. The hooding was intended 

 to permit the chicks to acquire enough control over their mus- 



