334 Jonrnal of Coinparatiz'C Xeurology and Psychology. 



I believe in)' series of experiments too limited to draw any 

 conclusions as to the effect of any particular sign in the field of 

 vision. My experiments lasted two months and were performed 

 ever)' other day, two trials being given each da)- 



It will be noticed that the experiment is borrowed from 

 Yerkes.' In a long series of experiments on frogs he came to 

 the conclusion that the frog observes colored cards and modi- 

 fies its actions according!)". 



Test XII. Efficiency of contact stimuli for following a path. 



It was suggested by Mr. G. H. Mead that the reactions of 

 the guinea pig might be direct responses to immediate con- 

 tact stimuli, and that a distant stimulus, e. g., a recollection o( 

 the path, Wds not responsible for the reaction. While it is 

 difficult for me to conceive how random movements could be 

 eliminated and a path followed accurateh' after two months, if 

 the performance were merel)' in terms of direct response to im- 

 mediate stimulus, nevertheless I welcomed the suggestion of 

 testing the part played by contact sensations in the learning and 

 recollection of the labyrinth. 



The labyrinth of text-figure 6 was taken into the dark room. 

 I used three animals which had never before been in the la- 

 byrinth but which were perfectlv tame. As the conditions for 

 all were the same, and this number was used only to ob\-iate 

 any error arising from individual variation (which proved to be 

 unimportant) I shall give a t)-pical series from one animal. 



The labyrinth was first learned in the light (electric). Car- 

 rot, as usual, was the food stimulus. Smoked paper was not 

 put on the floor. The tameness of the animals prevented long 

 delays as in the first experiments, and their activit)' was like that 

 in their home cages. 



Harvard Psvihological Stiidtes, \'ol. I, pp. 589-594. 



[42] 



