The Cricket: the Song 



across It. The rest of the wing-case presents 

 a few other veins of minor importance, 

 which keep the membrane taut without form- 

 ing part of the friction-apparatus. 



The left or lower wing-case is similar^ 

 constructed, with this difference that the bow, 

 the knob and the veins radiating from it now 

 occupy the upper surface. We find, more- 

 over, that the two bows, the right and the 

 left, cross each other obliquely. 



When the song has its full volume, the 

 wing-cases, raised high up and resembling a 

 pair of large gauze sails, touch only at their 

 inner edges. Then the two bows fit into 

 each other slantwise and their mutual fric- 

 tion produces the sonorous vibration of the 

 two stretched membranes. 



The sound appears to be modified accord- 

 ing as the strokes of each bow bear upon 

 the knob, which is Itself wrinkled, on the op- 

 posite wing-case, or upon one of the four 

 smooth radiating veins. This would go 

 some way towards explaining the Illusions 

 produced by music which seems to come from 

 here, there and everywhere when the timid 

 insect becomes distrustful. 



The Illusion of loud or soft, open or muf- 

 fled sounds and consequently of distance, 



349 



