ANATOMY AND PHYSIOLOGY 



105 



The tegmina are first spread a little ; then, as they close gradu- 

 ally, the scraper clicks across the teeth, making from twenty to 

 thirty sharp " tic "-like sounds in rapid succession. This call 

 guides the female to the male and when they are a few inches 

 apart she makes now and then a short, soft chirp, to which he 

 responds with a similar chirp, which is quite unlike the first 



FIG. 136. 



B 



Stridulating organs of Microcentrum lauri folium. A, dorsal aspect of -file (st) 

 when the tegmina are closed; B, ventral aspect of left tegmen to show file; C, dorsal 

 aspect of right tegmen to show scraper (s). 



call and, moreover, is made by the opening of the tegmina. 

 These and other details of the courtship may readily be ob- 

 served in twilight and even under artificial light, as the latter, 

 if not too strong, does not disturb the pair. Something sim- 

 ilar may be observed in the daytime in Orchelinmm, Xiphidium 

 and the tree crickets, (Ecanthus. The Stridulating areas are 

 usually membranous and the rasping organs are modified veins. 



