254 THE COURTSHIP OF ANIMALS 



reside in the hairs which are thickly distributed over the 

 legs and body. Now, hearing and touch are senses near 

 akin, and the vibrations produced by stridulation may be, 

 and probably are, received by, and interpreted through, 

 the medium of these hairs. For though the Scorpion may 

 not respond to sounds made by curious investigators, it 

 may be that they can perceive notes of a low pitch 

 imperceptible to our ears, such as are made by stridulat- 

 ing organs, as in the case of the Spiders. 



Perchance certain comb-like structures known as the 

 " pectines " may play a part in mate-hunting. These 

 are placed on either side of the under-surface of the body 

 between the last two pairs of legs. The fact that they are 

 larger in the male, and sometimes strangely modified in 

 the female, seems to show that they have some function 

 in relation to sex. They also appear to serve as sources 

 of information as to the nature of the ground traversed 

 by the animal, since they are long in species which walk 

 with the body raised high off the ground and short in 

 such as adopt a more grovelling posture. That the 

 Scorpions possess but a very limited means of gleaning 

 information of the outer world there can be no doubt. 

 How, then, do they find one another when that insistent 

 desire to mate begins to make itself felt ? Are the 

 " pectines " their informants through the sense of smell ? 

 Do the hairs scattered over the body act as sound-col- 

 lectors responding to the notes emitted by the stridulating 

 organs ? These are points on which information is much 

 to be desired. 



Our survey of the " Arthropoda," as those limb-bearing 

 jointed animals invested in a horny, or, more exactly, 

 a " chitinous " external skeleton are called has so far 



