336 Journal of Comparative Xeurology and Psychology. 



would have sig-nificance. Should the recollection of the path 

 be due to successive tactual sensations we would anticipate con- 

 fusion and a lengthening of the reaction time when the contact 

 stimuli have been changed. 



A labyrinth similar to the wire labyrinth in its proportions 

 was constructed of cardboard. (The advantage of the darkness 

 is now apparent, since the visual conditions were not modified. 

 The cardboard used had been purposely left in the experimental 

 cage when the latter was not in use, but even then the odor 

 conditions may have been slightly different.) Holes were made 

 in the cardboard food-box, and the door was swung from the 

 top as usual. A black cloth was spread over the floor of the 

 experimental cage to change still more the tactual conditions. 

 The electric wire was attached to the door to make contact 

 when the door should be pushed open. The guinea pig was 

 then brought to the dark room. 



Aug. 22. Time 1.75 min. 



In order to test whether this time was accidental another 

 trial was given. 



Repeated. Time .7s min. 



One would hesitate to lay much stress on the guinea pig's 

 sense of touch in comparison, e. g. , with that of the white rat, 

 because of the difference in the vibrissae. While the white rat's 

 vibrissae are long, motile, and extremely sensitive, those of the 

 guinea pig are shorter, coarse, and are not continually in use. 

 The hair of the guinea pig serves for a covering rather than for a 

 sense organ. I made a number of e.xperiments by touching 

 various parts of guinea pigs which were quite wild. If great 

 precaution be taken that the guinea pig shall see no move- 

 ment, its hair can be touched lightly at any accessible spot on 

 the body behind the head without causing a reaction. I never 

 succeeded in touching any part of the face without being seen. 



We have seen that there was no lengthening in the reac- 

 tion time when the contact conditions are changed, therefore 

 we infer that the path through a labyrinth is not learned solely^ 

 or even largely, in terms of tactual sensations 



