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THE AMERICAN NATURALIST [Vol. XLII 



In his earlier work on " Animal Education," Watson had made 

 such a general study of the behavior of the white rat as to 

 give a survey of the problems and methods for future work. He 

 and his collaborators have now undertaken a well-considered 

 campaign of intensive investigation in the different phases of 

 the rat's behavior. 



The matter selected for first attack is "the determination of 

 the relative importance of the several sensations of a given ani- 

 mal in its adjustment to its environment. ' ' What senses does the 

 rat use in finding its way about and what part does each sense 

 play? To this is devoted the main recent work from the Chi- 

 cago laboratory. 1 



Watson finds, as Yerkes did with the dancing mouse, that the 

 rat makes comparatively little use of senses that we are accus- 

 tomed to think of as the all-important ones. His conclusion 

 that sight, touch, hearing and smell play little, if any, part in 

 the rat's finding its way about may almost receive the usual 

 reportorial characterization of scientific results as "startling." 



The method of work was to place the rat at the entrance of 

 the complicated ' ' Hampton Court ' ' maze, with its many passage- 

 ways and blind alleys, and allow it to find its way to the central 

 compartment, where food had been placed. This was repeated 

 many times, till the correct path was completely learned; many 

 different rats were used, and a thorough study was made of the 

 rat's method of finding its way. The questions are essentially, 



(1) what senses does the rat use in learning the correct path; 



(2) what senses does it use in following the correct path after it 

 is learned ? 



To answer these questions, one or more senses were excluded, 

 in different specimens, either by operative procedure or by other 

 methods. The following extraordinary results were reached : 



1. Blinded rats, or those studied in complete darkness, learn 

 the path as quickly and follow it as readily as do those that 

 can see. Even if the path is learned in the light, blindness causes 

 no disturbance in later following it. (One rat formed an excep- 

 tion, finding its way in the dark only with the greatest difficulty.) 



2. Rats deprived of smell and of hearing do not differ from 

 normal ones in learning and following the correct path. This is 

 true even when these rats are likewise blinded. 



1 Watson,- J. B. Kinesthetic and Organic Sensations: their Role in the 

 Reactions of the White Rat to the "Maze. The Psychological Beview, Mon- 

 ograph Supplement, Vol. 8, No. 2, 1907, 100 pages. 



