FUNCTION OF VIBRISSAE IN BEHAVIOR OF WHITE RAT 13 



can be made in the light of some experimentation now to be 

 described. 



C. General Description of Problem 



All learning, human as well as animal no dotibt, consists in the 

 attainment of new or more perfect sense discriminations or in 

 new or more perfect motor adjustments and all advance is made 

 either by the formation of new sense impressions to relieve the 

 demand of a motor situation or of a new coordination to relieve 

 the stress of a sensuous stimulation ; but both these factors are 

 inseparable and both are concerned in every advance. 



Nevertheless we may arrange experimentation so as to throw 

 one or the other into prominence, to see how the habitual act 

 is broken up or disturbed by the addition or subtraction of sen- 

 sory stimulation, and what sense factors are requisite for a given 

 coordination. 



The following experimentation concerns itself with the acquire- 

 ment of a labyrinth habit and the discrimination of surfaces. 



It was believed that Dr. Watson was quite right in asserting 

 that his animals learned their maze by the use of kinaesthetic 

 sensations alone and that they learned it as perfectly and accu- 

 rately without vision, olfaction, etc., as before; but the maze 

 which he used was essentially a non-sensory maze for these 

 animals. It was made of wood, unpainted, therefore practically 

 uniform in color and brightness so that the keen sight of man 

 would scarcely have been any help in such a situation far less 

 the notoriously poor sight of the rat. The odor was fairly evenly 

 distributed except in the immediate vicinity of the food box 

 where there was always halting and hesitating in the early 

 trials of an animal and the tactual and auditory conditions 

 were, so far as could be seen, not more marked in one part of 

 the maze than in another. 



But one cannot reason from this maze to all mazes, nor from 

 conduct in such a situation to conduct where sensory factors are 

 more strong and more varied as they are in conditions of nature 

 where animals run in the open either for food, from danger, or 

 to their holes. 



It cannot be argued that because animals can learn an intricate 

 coordination without vision, hearing, etc., that if strong visual 

 elements were present they might not help or hinder, as the case 

 might be, the formation of the coordination. 



