Page:Insects - Their Ways and Means of Living.djvu/61

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THE GRASSHOPPER'S COUSINS

length. The front wings are long and narrow (Fig. 63, W2), somewhat stiff, and of a leathery texture. They are laid over the thinner hind wings as a protection to the latter when the wings are folded over the back, and for this reason they are called the tegmina (singular, tegmen). The hind wings, when spread (W3), are seen to be large fans, each with many ribs, or veins, springing from the base. These wings are gliders rather than organs of flight. For most grasshoppers leap into the air by means of their strong hind legs and then sail off on the outspread wings as far as a weak fluttering of the latter will carry them. One of our common species, however, the Carolina locust (Frontispiece), is a strong flyer, and when

Fig. 15. A grasshopper, Chloealtis conspersa, that makes a sound by scraping its hind thighs over sharp-edged veins of its wings
A, the male grasshopper, showing the sound-making veins of the wing (b). B, inner surface of right hind leg, showing row of teeth (a) on the femur. C, several teeth of the femur (enlarged)

flushed flits away on an undulating course over the weeds and bushes and sometimes over the tops of small trees, but always swerving this way and that as if undecided where to alight. The great flights of the migratory locusts, described in the last chapter, are said to have been accomplished more by the winds than by the insects' strength of wing.

The locusts are distinguished by the possession of large

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