120 The Animal Mind 



tuning forks near them or their webs, only the web-making 

 species gave any response. These latter would not react 

 to ordinary noises, nor to the sound of a small fork, but to 

 the humming of a large fork they responded always by 

 raising the front legs, and sometimes by dropping from their 

 webs (570). Two Texan species that were experimented 

 upon by placing them in a cage free from vibration gave no 

 response whatever to tuning forks of various pitches or to 

 other sounds (618). It seems, then, highly probable that 

 spiders are sensitive only to vibrations communicated to 

 their webs, and very likely these furnish tactile rather than 

 specific auditory stimulation. The observation of Boys 

 may be quoted: "On sounding an A fork, and lightly 

 touching with it any leaf or other support of the web or 

 any portion of the web itself, I found that the spider, if at 

 the centre of the web, rapidly slews around so as to face the 

 direction of the fork, feeling with its fore feet along which 

 radial thread the vibration travels. Having become 

 satisfied on this point, it next darts along that thread till it 

 reaches either the fork itself or a junction of two or more 

 threads, the right one of which it instantly determines as 

 before. If the fork is not removed when the spider has 

 arrived it seems to have the same charm as any fly, for the 

 spider seizes it, embraces it, and runs about on the legs of 

 the fork as often as it is made to sound, never seeming to 

 learn by experience that other things may buzz besides its 

 natural food. If the spider is not at the centre of the web 

 at the time that the fork is applied, it cannot tell which way 

 to go until it has been to the centre to ascertain which radial 

 thread is vibrating." If, however, it has followed the fork 

 to the edge of the web, and the fork is then withdrawn and 

 brought near again, the spider reaches out in its direction. 

 If the spider is at the centre of the web and a sounding fork is 



