132 E. S. BOGARDUS AND F. G. HENKE 



After the five normal and six blind rats had learned maze I, 

 they were taught mazes II, III, IV, and V (see fig. i) in succes- 

 sion. Our object here was to study the function of the contact 

 sensations in making readjustments to slightly altered con- 

 ditions. The same general results obtained. All rats became 

 confused in the new situation and were forced to make a new 

 adjustment by the trial and error method. During the period of 

 confusion the animals fell back upon the use of contact sensations 

 and continued to rely upon them until they reached a familiar 

 unit in the maze. The number of contacts again varies with 

 the number of errors made. Table III gives a typical detailed 

 record for a blind rat. 



In bringing to a close this description of the experiments, it 

 is evident that tactual sensations of the nose and head are util- 

 ized in learning the maze, and this implies that they are used 

 in getting the kinaesthetic and organic cues. The facts which 

 we offer in substantiation are: (a) the percentage of corners 

 touched, beginning high, gradually decreases as the movements 

 of the rat become automatic; (b) a striking correlation exists 

 between the number of contacts and the number of errors; (c) 

 a general correlation between increase and decrease of time, 

 and of the number of corners touched; (d) tactual sensations 

 are no longed used when the maze is learned; (e) when the 

 kinaesthetic and organic cue is lost at any point in the maze, 

 the rats rely upon head and nose contact; (f) the conclusions 

 hold for both normal and blind animals and indicate a minimal 

 effect of -vision. 



As indicated, the maze used in this experiment was constructed 

 so that the pathw^ay could be altered in various ways. This 

 type of construction was designed for the purpose of studying 

 the effects of the maze experiences upon subsequent behavior 

 in slightly altered conditions. While our experiments were con- 

 cerned primarily with the function of contact sensations in 

 learning to make adjustments to new or slightly modified situ- 

 ations, yet they yielded some incidental results bearing upon 

 the former problem which are of sufficient interest to merit a 

 short discussion. 



A reference to fig. i will show the successive alterations effected. 

 In maze II, door 5 was placed at 6, while door 3 was opened. 

 Maze II was altered by placing door 2 at 3 and by opening 5. 



