1 10 The Animal Mind 



and sometimes by dropping from their webs (320). 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 (351). 

 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 stimu- 

 lation. 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 junc- 

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 to the edge of the web, and the fork is then withdrawn and 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

 brought near without touching the web, the spider does not 

 reach for it, but drops down at the end of a thread. If the 

 fork touches the web again, the spider climbs the thread and 

 finds the spot very quickly (69). 



