INSECTS
trees, underbrush, and weeds can not but make their downward journey one of many a bump and slide from leaf to leaf before the earth receives them.
The creatures are too small to be followed with the eye as they drop, and so their actual course and their behavior when the ground is reached are not recorded. But several hatched indoors were placed on loose earth packed
Fig. 126. The young cicada nymph ready to enter the ground (greatly enlarged)
flat in a small dish. These at once proceeded to get below the surface. They did not dig in, but simply entered the first crevice that they met in running about. If the first happened to terminate abruptly, the nymph came out again and tried another. In a few minutes all had found satisfactory retreats and remained below. The eagerness with which the insects dived into any opening that presents itself indicates that the call to enter the earth is instinctive and imperative once their feet have touched the ground. Note, then, how within a few minutes their instincts shift to opposites: on hatching, their first effort is to extricate themselves front the narrow confines of the egg nest, and it seems unlikely that enough light can penetrate the depths of this chamber to guide them to the exit; but once out and divested of their encumbering embryonic clothes, the insects are irresistibly drawn in the direction of the strongest light, even though this takes them upward—just the opposite of their
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