Annie Trumbull Slosson.
MIMICRY
Protective mimicry as it occurs in animals may be the simulation in form or color, or both, of natural objects, or it may be the simulation of the form and color of another animal, which for some reason enjoys immunity from the attacks of species which ordinarily prey upon its kind. Of course this mimicry is unconscious and is the result of a slow process of development which has, no doubt, gone on for ages.
Remarkable instances of mimicry, in which things are simulated, are found in the insect world. The "walking-sticks," as they are called, creatures which resemble the twigs of trees; the "leaf-insects," in which the foliage of plants is apparently reproduced in animate forms; the "leaf-butterfly" of India, in which the form and the color and even the venation of leaves are reproduced, are illustrations of mimicry which are familiar to all who have given any attention to the subject.
Repulsive objects are frequently mimicked. A spider has been lately described from the Indo-Malayan region, which, as it rests upon the leaves, exactly resembles a patch of bird-lime. The resemblance is so exact as to deceive the most sagacious, and the discovery of the creature was due to the fact that the naturalist who happened to see it observed, to his surprise, that what he was positive was a mass of ordure was actually in motion. A similar case of mimicry is observable among some of the small acontiid moths of North America. One of these is pure white, with the tips of the fore wings dark greenish-brown. It sits on the upper side of leaves, with its fore wings folded over, or rolled about the hind wings, and in this attitude it so nearly approximates in appearance the ordure of a sparrow as to have often deceived me when collecting.