and Imitative Forms as a Means of Self-Protection

���Above, a number of seed-like Membracidae from tropical South America. They are probably overlooked by all but the most astute insect- eating birds in search of a meal

At left, an extraordinary insect with a huge, helmet- like expansion of the pro- thorax. This is so large in some insects that they are completely covered by it

��Below, a strange look- ing insect which, when alive, looks as if it were being attacked by a spider. This is really the insect's armor plate

��At right: The apparent body and formidable sting of this insect are a mere pretense, being only a homy outgrowth from the thorax

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