38 L. W. SACKETT 



9. The experimenter was in the cage at all times with a defi- 

 nite position while the animal worked. 



The writer is aware of the severe criticism which is being di- 

 rected toward this custom and the oft repeated cautions con- 

 cerning the "elimination of the experimenter." The points are 

 well taken as special cases but are hardly to be considered 

 general laws. If the writer is not mistaken, the controversy 

 arose from, or at least was brought to a climax by the behavior 

 of Haggerty's dog in his reactions to the area stimulation with 

 and without the leash although the experimenter was attempt- 

 ing not to direct the dog's action by means of the leash. This, 

 the writer recognizes as the most probable thing to expect 

 with an animal bearing the close attachment to man which the 

 dog does. One would expect them to be peculiarly sensitive to 

 the wishes of the master. The same tendency would be true 

 with the horse and was with the famous "Hans." It would 

 be less true in the case of other animals unless the stimulus 

 should arouse fear. In the case of a semi-solitary animal like 

 the porcupine, where there is certainly no social relation with 

 man, the presence of the experimenter would probably be less 

 significant. 



Porcupine No. 3 was used also with the puzzle -box. The 

 method with him and his rate of learning was nearer that of 

 No. 4 than of No. 11. Whether the rapidity of No. 11 was 

 due to individual differences or difi:erence in the method is not 

 certain. It is probable that too much practice was given on 

 the separate parts with Nos. 3 and 4. Too much experience 

 served to fix the new habit so strongly that it was a hindrance 

 to the forming of later associations. It would seem even with 

 animals to be pedagogically wrong to give too extensive drill 

 on any isolated step no matter how fundamental it may be. 

 Or, put as a general proposition, there probably is a point of 

 efficiency, difi"erent for each individual, where retention of the 

 old and advance to the new is most easily accomplished. If 

 this is not attained, the habit is effaced in the next series of 

 associations. If it is exceeded, injurious inhibitions, even to 

 the extent of arrested development may be set up and progress 

 is more difficult. No. 3, however, mastered the devices and 

 combinations very readily for the reason, if for no other, that 

 he was a most persistent worker. 



