Page:Insects - Their Ways and Means of Living.djvu/45

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The Grasshopper


hopper emerges from it, carefully pulling its legs and antennae from their containing sheaths. The whole process consumes only a few minutes. The emerged grasshopper is now entering its third stage after hatching, but the shedding of the hatching skin is usually not counted in the series of molts, and the first subsequent molt, then, we will say, ushers it into its second stage of aboveground life. In this state the insect is different in some respects from what it was in the first stage: it is not only larger, but the body is longer in proportion to the size of the head, as are also the antennae, and particularly the hind legs. Again the insect becomes active and pursues its routine life for another week; then it undergoes a second molting, accompanied by changes in form and proportions that make it a little more like a mature grasshopper. After shedding its cuticula on three succeeding occasions, it appears in the adult form, which it will retain throughout the remainder of its life.

The grasshopper developed its legs, its antennae, and most of its other organs while it was in the egg. It was hatched, however, without wings, and yet, as everyone knows, most full-grown grasshoppers have two pairs of wings (Fig. 63, W2, W3), one pair attached to the back of the middle segment of the thorax, the other to the third segment. It has acquired its wings, therefore, during its growth from youth to maturity, and by examining the insect in its different stages (Fig. 9), we may learn something of how the wings are developed. In the first stage, evidence of the coming wings is scarcely apparent, but in the second, the lower hind angles of the plates covering the back of the second and third thoracic segments are a little enlarged and project very slightly as a pair of lobes. In the third stage, the lobes have increased in size and may now be suspected of being rudiments of the wings, which, indeed, they are. At the next molt, when the insect enters its fourth stage, the little wing pads are turned upward and laid over the back, which disposition not only

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