THE SENSES AND THEIR ORGANS. 303 



interval I again tried the fork to the sides of the web. This time Domicile 

 was again deceived, and turned towards the point of agitation as in pre- 

 vious cases. She had evidently forgotten her former experience in the brief 

 intervening space. 



The conclusion which I draw from such an experiment is that the 

 spider was affected by the vibratory motions of the fork, communicated 

 through the taut elastic line to the hairs and spines of the feet. 

 . ,- The sense of touch was the only means of communicating the 

 by Touch. ^S^^^^^°^^' and no other indications of the spider having heard 

 the sounds of the fork were here shown than appear in the cap- 

 ture of an insect under well known and ordinary circumstances. Certainly 

 the theory has never been advanced, and could not be maintained, that the 

 spider hears the motion of an entangled insect's wings and runs to secure 

 the victim at such a signal. In .such case it is manifest that the spider 

 feels the action of the struggling captive as it is communicated over the 

 vibrating radii to her feet, which grasp them at the centre of lier snare. 

 If this be so, it seems to me equally manifest that the same sense was 

 brought to bear in determining the position of the tuning fork in the 

 above and like experiments. 



I may venture to give the record of another experiment with the tun- 

 ing fork, which was also wrought upon a Domicile spider. The vibrating 

 fork was placed near her as she sat upon the hub, and moved around her 

 four times, the spider showing no symptoms of perceiving the vibrations. 

 The fork was approached within a few millimetres of the hind legs, where- 

 upon she showed excitement. This was again repeated a number of times, 

 the spider showing no signs. I quote the notes : " The vibrating fork is 

 next touched to a radius on one side of the web. The spider turns and 

 runs out towards the point of contact. After one minute's interval the 

 orb was touched on the opposite side. Domicile leaves the hub, runs out 

 a little ways towards the fork, hangs ujton the radial line, waves one fore 

 foot around through an open space torn by the rain just below the hub, 

 then returns to the hub. 



"One minute interval. Tlie fork is applied to a radius at the top of 

 the web. Domicile makes same demonstrations as before. One minute 

 interval. The fork is applied within a half inch of the spider's face as 

 she hangs upon the hub. She stretches out one fore leg as on guard. 

 One minute interval. The exjaeriment is repeated. The fore legs are both 

 thrown out quickly, violently, as though to grasp something. After one 

 minute the experiment is repeated three times. Tlie first two are unno- 

 ticed. At the third application Domicile shoots out her fore legs. After 

 the same interval the fork is tried at one side and at the toi? of the web 

 several times. No response. It is then placed upon the web at the other 

 side. The sjsider runs towards the fork. Various trials are made at the 

 same and other points, and all fail to elicit a response." 



