CRICKETS AND EARWIGS 



155 



is a long, oval, transparent, membranous disc, stretched 

 over a corresponding aperture in the walls of the leg 

 (Fig. 48), and exactly opposite it, on the 

 other side of the leg, there is a similar, 

 but round and much smaller disc. Be- 

 tween these two, in the centre of the 

 hollow shaft of the leg, is a bladder-like 

 expansion of the main breathing tube of 

 the leg. Numerous curiously shaped 

 nerve-endings, having the peculiar form 

 of those of special sense, are distributed 

 at this spot, and the action of the compli- 

 cated apparatus seems to be such that the 

 membranous disc, vibrating in response to FIG. 48. Fore 



,, , . . ,. , , . ,. ., , Tibia of Cricket, 



the chirping ot some distant individual, showing audi- 

 communicates its motion to the air within 

 the breathing-tube, which in its turn affects the neigh- 

 bouring nerves, thus enabling the insect to perceive the 

 sound. 



Projecting from the hinder part of the female's body 

 is a long ovipositor, consisting of a double boring 

 implement, used in depositing the eggs in suitable situa- 

 tions. Large numbers of eggs are laid, and the course 

 of development is similar to that of the cockroach, 

 the eggs yielding small, active, six-legged creatures, 

 something like their parents in form. After a series 

 of moults, these attain by progressive changes, but 

 without any pause in their activity or suspension of 

 their functions, the adult size and form, acquiring 

 wings only at the last moult. The metamorphosis is 

 thus incomplete. 



Two long, un jointed, tapering appendages, pointing 

 backwards, project from near the extremity of the 

 abdomen in both sexes. They are furnished abundantly 



