No. 2.] MENTAL POWERS OF SPIDERS. 391 



brought to one side of her, when she not only moved the first 

 legs, but also the leg of the second pair on the side toward 

 the fork. It would tire the reader unnecessarily were we to 

 describe the check experiments that were made after each 

 observation, but we felt their importance, and never failed to 

 make them ; in fact, our check experiments were more numer- 

 ous than our direct ones. 



Later on tests similar to those given above were made on a 

 smaller spider, a female of E. labyrhithca, as she stood in her 

 web. In this instance she responded to all the forks, A, B, 

 and C. 



Second and third large individuals of E. strix acted as the 

 first had done, responding to the large fork, but not to the 

 small ones. On the other hand, five small individuals of strix 

 were much excited by the small forks. Subsequent observation 

 left no room for doubt that the large spiders, with few excep- 

 tions, only attended to the sound produced by the large forks. 



To show the results of our experiments and also the way in 

 which we worked we quote from our notes. 



July 14. — Held the big fork, in vibration, over a large male 

 of E. iiisiilaris, an inch and a half away. He threw up his first 

 legs, making frantic efforts to reach it. When the fork was 

 removed he settled down quietly in his web. This was repeated 

 ten times, always with the same result. A female of this 

 species acted as the male had done, but seemed less excited by 

 the vibrations. Unless the fork was sounding neither spider 

 paid any attention to it. 



July 18. — Held the large fork, in vibration, near a female 

 of E. infuinata standing quietly on a wire screen. She did not 

 move. Repeated the test with the fork, at first vibrating and 

 then still, ten times without result. She was then placed in the 

 web of another spider, and the B fork was brought near her as 

 she stood there. She appeared frightened, and at once threw 

 up the first and second pairs of legs. The fork was next held 

 behind and to one side, so that she could not see it; but she 

 seemed to hear it, since she turned toward the fork and almost 

 fell backward in her efforts to reach it. The fork was now held 

 in front of her again, when she moved her legs as before. This 

 experiment was repeated many times with like results. To 

 hear the fork when she could not see it evidently excited her 



