434 'Journal of Comparative Neurology and Psychology 



C. Do. The 32 c.p. to the right side. 



D. While the worker was on the stage, I substituted an 8 c.p. lamp for the 32 c.p. 



E. While the worker was on the stage, I transferred the 8 c.p. lamp to the left side. 



F. Do. 8 c.p. lamp to the right side. 



G. While the worker was on the stage, I substituted a 4 c.p. for the 8 c.p. 



H . While the worker was on the stage, I transferred the 4 c.p. to the left side. 



I. Do. 4 c.p. lamp on the right side. 



K. While the worker was on the stage, I substituted a 32 c.p. lamp for the 4 c.p. 



L. While the worker was on the stage, I placed the 32 c.p. at the back of the stage. 



M. Do. 32 c.p. at the front of the stage. 



Fig. 18. Learning-curve of an individual Formica fusca var. subsericea Say, illustrating its reactions 

 to odors of the pathway and to tactile stimuli. 



Apparatus, cardboard stage with white incline on the left. Illumination by incandescent lamps; 

 practically uniformly illuminated. 



A. While the ant was in the nest, a new white incline was substituted for the old. 



B. The old incline was substituted for the new. 



C. While the worker was on the stage, a new white incline was substituted for the old. 



D. Do. an incline with a three-fourths inch transverse band of oil of cloves across its middle was 

 substituted for the other. 



E. Replaced the old incline. 



F. Do. an incline with middle three-fourths inch band of xylol for the other. 



G. Do. with fresh rylol band. 



H. Do. with fresh band of cedar oil. 



I. Do. with fresh band of oil of cloves. 



K. Do. with unscented white incline. 



L. Do. with smooth black incline. 



M. Do. with black incline with velvety surface. 



