INSTINCT AND INTELLIGENCE 



wing, she dropped it about six inches away, ran into the 

 nest, out again and over to the grasshopper, which she 

 straddled and carried by the head to the entrance. 

 She then ran down head first, turned around, came up, 

 and seizing it by the head, pulled it within. On the 

 following day, when she had brought a grasshopper to 

 the entrance of the nest, and while she was below, we 

 moved it back five or six inches. When she came out, 

 she carried it to the same spot and went down as before. 

 We removed it again, with the same result, and the 

 performance was repeated a third and a fourth tune, 

 but the fifth time that she had found her prey where we 

 had placed it she seized it by the head, and going back- 

 ward dragged it down into the nest without pausing. 

 On the next day the experiment was repeated. After 

 we had moved the grasshopper away four times, she 

 carried it into the nest, going head foremost. On the 

 fourth and last day of our experiment, she replaced the 

 grasshopper at the door of the nest and ran inside seven 

 times, but then seized it and dragged it in, going back- 

 ward. How shall this change in a long-established 

 custom be explained, except by saying that her intelli- 

 gence led her to adapt herself to circumstances? She 

 was enough of a conservative to prefer the old way, but 

 was not such a slave to custom as to be unable to vary it. 

 I 305 



