THE WHITE RAT AND THE MAZE PROBLEM 3 



It must also be remembered that many experimenters who have 

 attacked this problem fail to separate in their detailed results 

 and conclusions the typical learning process, which is shown 

 chiefly in the first few trials, and the perfecting of the automa- 

 tism, the acquisition of speed, which follows. Possibly Pro- 

 fessor Watson's work may bear this criticism. 



The third line of evidence comes from attempts to introduce 

 visual clues at critical points in the maze. Small fixed colored 

 posts at such places and also varied the direction of the light 

 which fell upon the maze. He concluded that the use of vision 

 was not shown by any discrimination or recognition. 4 Miss 

 Allen marked the path for another rodent, the guinea pig, with 

 colored cards but her results were negative. 5 Professor Watson, 

 in the case of one rat, used colored lights with no perceptible 

 effect. 6 All of these objects were stationary. It is possible 

 that moving objects might have been better. Rats are hyper- 

 metropic and such animals may well fail to respond to near 

 objects in any discriminating way. 



The fourth form of attack upon the visual powers of these 

 animals consists in observations of the animals and experiments 

 with them in the dark and in the light respectively and noting 

 the amount of activity and the accuracy of movement. Opin- 

 ions differ slightly here. Slonaker shows in his studies of the 

 activity of the white rat that its greatest period is during the 

 night, beginning with the first shadows of afternoon. He says 

 that the average distance traveled is five miles per night as 

 against one-tenth of a mile per day and concludes that light 

 normally does have an influence upon the animal's activity. 7 

 A few of Yerkes' dancers seemed somewhat disturbed by tests 

 in the darkness. 8 Miss Allen found that her guinea pigs made 

 more random movements in the darkness than in the light. 9 

 So far as I know no one has followed this lead further. It 

 would be an interesting bit of experimental work. 



4 Op. cit. 



5 Allen, Jessie. Association in the Guinea Pig. Jour. Comp. New. and Psy- 



chol, vol. 14. 1904. 



6 Op. cit., p. 43. 



7 Slonaker, J. P. The Normal Activity of the White Rat at Different Ages. 



Jour. Comp. Nenr. and Psychol., vol. 17, p. 342. 1907. 



8 Yerkes, R. M. The Dancing Mouse. P. 189. 1907. 



9 Op. cit. 



