SCORPIONS 79 



index finger backwards and forwards in a direction transverse to 

 its coarse edges over the ends of the teeth of a very fine-toothed 

 comb. The stridulatory apparatus consists of a scraper on the flat 

 outer face of the basal segment of the pedipalps and a rasp on the 

 equally flat inner face of the corresponding segment of the first 

 pair of legs. The scraper is tolerably thickly, but regularly, beset 

 with stout conical sharp spinules like a tiger's canine, only more 

 curved towards the points, some of which terminate in a long, 

 limp hair, while the rasp is studded with minute tubercles shaped 

 like the tops of mushrooms. 



There is no evidence that scorpions or large spiders can hear the 

 sounds that their own stridulating organs produce, and Pocock 

 (1896) points out that many poisonous animals including wasps and 

 snakes are frequently rendered conspicuous by bright and staring 

 colours or by sound-producing organs which, when in action, 

 serve as a danger signal to meddlesome intruders, warning them 

 to beware of hostile interference. In this way the poisonous forms 

 are not destroyed by carnivorous creatures in mistake for other 

 harmless and edible species. The existence of stridulatory organs 

 implies the existence of an auditory sense, not necessarily in the 

 performers themselves, but only in the enemies that might other- 



Scraper 

 ■Rasp 



Fig. 19. Stridulatory apparatus of a scorpion. 1. Coxa of claw 

 with rasp. 2. Coxa of first leg with scraper. (After Pocock, 1896.) 



wise destroy them. The fact that monkeys, which are partial to a 

 diet of scorpions and skilful enough to handle them without damage, 

 pay no heed to the hissing when searching for these animals be- 

 neath stones does not detract from the theory. Despite their warn- 

 ing colours, bees are devoured by frogs and toads and the cobra is 



