294 



FREDERICK S. BREED 



and only 2 to S. The plan of the work was interfered with 

 somewhat by the necessary retirement of no. 70. After 120 

 trials this animal was unable to continue on account of physical 

 debility, an unfortunate failing of these laboratory chicks after 

 a given period. No. 70, however, showed signs of acquiring the 

 small-large habit, for in its last 50 trials there were 38 reactions 

 to S and 12 to L. No. 83 remained in the experiment with the 

 positive result shown in table 3, which follows: 



TABLE 3 



Small-Large Reactions 



Chick No. 83. Sex, M. 



Hatched December 12, 1908 



Series Date Right Wrong 



SUMMARY AND CONCLUSIONS 



The chicks in advance of training selected the brighter of 

 two non-chromatic stimuli. 



According to the human standard of brightness values, a 

 similar law did not hold for chromatic stimuli. This exception 

 points in the direction of one or both of the following conclusions : 



(1) A difference exists between the chromatic luminosity 

 values for the chick and those for the human; 



