SCORPIONS 77 



the two sexes together during mating. An alternative suggestion 

 has been made that their function is to clean the extremities of the 

 pedipalps, legs and tail. In 1883 Lankester made experiments on 

 the tactile sense of the pectiniform appendages, and wrote: 'They 

 appeared to me to possess no special sensitiveness. When they 

 were pinched with forceps, the scorpions showed no sign of dis- 

 comfort. It is quite possible that they may acquire a heightened 

 sensibility at the breeding season, and serve as guides to the male 

 and female in effecting copulation.' A few years later, nerve ter- 

 minations were discovered in the lamellae of the pectines of scor- 

 pions by Gaubert, who wrote: 'II est incontestable que leur richesse 

 en nerfs en fait des organes sensitifs.' 



Pocock (1893) suggested that the pectines were tactile organs of 

 some importance. He pointed out that their situation near the 

 genital aperture, their larger size in males and the modification of 

 their basal portion in females of the same species indicated some 

 sexual function. Apart from this he considered that it was highly 

 probable that they were useful organs of touch in other aspects of 

 life, enabling their possessor to learn the nature of the surface over 

 which it was walking. He added: 'In favour of this view may be 

 adduced the fact that these animals have been seen to touch the 

 ground with their combs. Moreover, it is a very noticeable circum- 

 stance that scorpions which, like Euscorpius, creep along with their 

 bellies close to the ground, have very short combs while in others 

 which, like Parabuthus, stand high upon their legs, the combs are 

 exceedingly long. I once noticed a Parahuthus marching over a 

 piece of dead cockroach. When she had half crossed it, instead of 

 going straight ahead as was expected, she halted abruptly, backed 

 a little and stooping down started to devour the fragment. From 

 the height at which the body was being carried, I am persuaded 

 that no portion of the lower surface, except the combs, could have 

 come into contact with the piece of food; so there can be little 

 doubt that its presence was detected by the organs in question.' 



Shortly afterwards it was suggested that the pectines of scor- 

 pions, like the special sense organs oi Limulus, and of Galeodes and 

 other Arachnids were probably to be accredited with the functions 

 of equilibration and audition, but Warburton [in Harmer and 

 Shipley, 1909)* supported Pocock's (1893) view. 



