XIV SENSES INTELLIGENCE m 



exceedingly strange that the nomadic and hunting spiders, to 

 which the sense of hearing might be expected to be extremely 

 useful, should be deficient in this faculty, while the sedentary 

 spiders, to which it would appear comparatively unimportant, 

 should possess it in a tolerably developed form. That writer may 

 possibly be correct in supposing that the sense, as possessed by 

 spiders, is hardly differentiated from that of ordinary touch, and 

 that the web-making species are only aware of sounds by the 

 vibrations communicated to their feet by the medium of the 

 web. However this may be, we must reluctantly but sternly 

 reject the numerous and seemingly authentic stories, often con- 

 nected with historic personages, which credit the spider with a 

 cultivated taste for music. 



We have seen that among the spiders which possess a stridu- 

 lating apparatus it is confined, in certain groups, to the male, or 

 if present in the female it exists only in a rudimentary form. 

 If in these cases stridulation has been rightly interpreted as a 

 sexual call, the power of hearing, at least in the female, is of 

 course connoted. The spiders in question are members of the 

 Theridiidae, a family closely allied to the Epeiridae, and therefore 

 more likely than most groups to possess the power of hearing. 



Theraphosid spiders show no response to the stimulus of 

 sound, and among them stridulation is not confined to one sex. 

 If, as is generally believed, the organ is used to warn off enemies, 

 it is not necessary that the sound produced should be audible to 

 the spider itself. If there be any true hearing organ in spiders 

 its location is quite uncertain. Some have supposed the so-called 

 lyriform organs in the legs to have an auditory function, while 

 others have supposed the power of hearing to reside in certain 

 hairs, of which there are several different types distributed over 

 the body and limbs of the animal. 



Spider Intelligence.-^The experiments performed by the 

 Peckhams clearly proved that spiders have short memories — a 

 sure indication of a low state of intelligence. Members of the 

 Lycosid or " Wolf-spider " group, when deprived of their cocoons, 

 recognised them again after a few hours, but in most instances 

 they refused to resume them after a lapse of twenty-four hours, 

 and in every case an absence of two days sufficed to prevent any 

 sign of recognition on their restoration. Moreover, when, after a 

 shorter interval, the cocoons of other spiders, even of different 



