Page:Insects - Their Ways and Means of Living.djvu/67

 bases of the front wings, or tegmina. On this account the front wings of the males are always different from those of the females, the latter retaining the usual or primitive structure. The right wing of a female in one of the more grasshopperlike species, Orchelimum laticauda (Fig. 30), is shown at C of Figure 18. The wing is traversed by four principal veins springing from the base.

The one nearest the inner edge is called the cubitus (Cu) and the space between it and this margin of the wing is filled with a network of small veins having no particular arrangement. In the wings of the male, however, shown at A of the same figure, this inner basal field is much enlarged and consists of a thin, crisp membrane (Tm), braced by a number of veins branching from the cubitus (Cu). One of these (fv), running crosswise through the membrane, is very thick on the left wing, and when the wing is turned over (B) it is seen to have a close series of small cross-ridges on its under surface which convert it into a veritable file (f). On the right wing this same vein is much more slender and its file is very weak, but on the basal angle of this wing there is a stiff ridge (s) not developed on the other. The katydids always fold the