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ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



uppermost. He found also that they keep the wings through life 

 iD whatever position they have at maturity, but that if the wings 

 are changed artificially at the last molt before they become dry and 

 stiff the crickets kept them in this altered position and when mature 

 sing as well as any of the others. Amongst the females a larger 

 percentage have the left wing normally on top. 



The front wings of male crickets are usually very broad and have 

 the outer edges turned down in a wide flap that folds over the sides 

 of the body when the wings are closed. The wings of the females 

 are simpler and usually smaller. The differences between the front 



Sc R M 



i i / 



Sc R M 



Fig. 19. — The wings of a tree cricket. A, right front wing of an immature female, show- 

 ing normal arrangements of veins : 8c, subcosta ; R, radius ; M , media ; Cih, first branch 

 of cubitus ; (7« 2 , second branch of cubitus ; 1A, first anal. (From Comstock and Need- 

 ham.) B, front wing of an adult female of the narrow-winged tree cricket. C, front 

 wing of an immature male, ohowing widening of inner half to form vibrating area or 

 tympanum, and modification of veins in this area. (From Comstock and Needham.) 

 D, right front wing of adult male of the narrow-winged tree cricket, with veins iden- 

 tified according to Comstock and Needham. The second branch of cubitus (Ctt 2 ) be- 

 comes the curved file vein (fv). 8, the scraper 



wings in the male and the female of one of the tree crickets (fig. 23) 

 is shown at B and D of Figure 19. The inner half of the wing (or 

 the rear half when the wing is extended) is very large in the male 

 (D) and has only a few veins, which brace or stiffen the wide mem- 

 branous vibratory area or tympanum. The inner basal part or anal 

 area of the male wing is also larger than in the female and contains 

 a prominent vein (Ou 2 ) which makes a sharp curve toward the edge 

 of the wing. This vein has the stridulating file on its under surface. 

 The veins in the wing of an adult female (B) are comparatively 

 simple, and those of a young female cricket (A) are more so. But 

 the complicated venation of the male wing has been developed from 



