58 



FREDERICK S. BREED 



The openings were the same in shape and one was approximately 

 twice the size of the other. The experiment was undertaken 

 with chicks no. 24 and no. 25, and completed with the result 

 detailed in table 19. The training was finished quite satis - 



TABLE 19 



Reactions to Size: Small- Large Openings 

 Chicks nos. 24 and 25. Hatched 2/5, '08 



a; 

 1.. 

 2.. 

 3.. 

 4.. 

 5.. 



6.. 



7.. 



9. 

 10. 

 11. 



Series 



Control Tests 



Card of small opening brighter, and its electric box brighter: 

 1 * Mar. 24 9 1 



Card of large opening brighter, its electric box brighter: 

 2 Mar. 24 9 1 



Cards equally illuminated, electric box of small opening made the brighter by 

 illumination of electric light: 

 3 Mar. 24 9 1 



Card of small opening brighter, electric box of large opening made much darker 

 by overhead cardboard: 

 4 Mar. 24 10 



Cards equally illuminated, electric box of large opening made the darker by over- 

 head cardboard: 

 5 Mar. 25 10 



factorily and within a reasonable time limit, so the method 

 seemed available for further use. Five control series were given 

 to check out the influence of brightness. It is manifest that 

 with equal illumination on the faces of the display-cards, which 

 was roughly secured by adjustment of the shades of the two 

 windows that admitted light to the room, the electric box back 



