No. 391.] THE WINGS OF INSECTS. coy 
by a modification of the cubital and anal areas. An extreme 
case of this is furnished by the male CEcanthus (Fig. 79). The 
principal vibrating area of the wing lies between the branches 
of the cubitus, which diverge widely in this sex. 
A study of the musical organs of adult Orthoptera throws 
light on the nature of the anal furrow. In the female this fur- 
row lies between the cubitus and the first anal vein; but in the 
males of the Locustide and Gryllide the anal furrow crosses 
Fic. 78. — Wings of a female nymph of (Ecanthus. 
vein Cuz. It is evident, therefore, that this furrow is merely 
a fold in the adult wing, and that its position is variable. It 
has already been shown 1 that in the Heteroptera, when an anal 
furrow is developed, it is in front of the cubitus, instead of in 
the more usual position between the cubitus and the first anal 
vein. 
Although the wings of the two sexes of CEcanthus present 
a very different appearance, there is really a very close corre- 
spondence in the tracheation (and consequently in the vena- 
1 American Naturalist, vol. xxxii, p. 252. 
