. Text book of zoology. Zoology. VI. Biology. 6. Protective Adaptations. 71 Other means of protection are of a purely defensive nature, and here there is a great diversity. Many animals try to escape danger hy flight, and many weak and defenceless fonns have remarkable powers in this direction { Antelopes). Others save themselves by hiding. Many offer resistance in the shape of a specialised protective covering (a prickly skin, a stiff coat of mail). Not a few Insects are characterised by a repulsive taste or odour, and by this keep the enemy at a distance; many animals are protected, whet
. Text book of zoology. Zoology. VI. Biology. 6. Protective Adaptations. 71 Other means of protection are of a purely defensive nature, and here there is a great diversity. Many animals try to escape danger hy flight, and many weak and defenceless fonns have remarkable powers in this direction { Antelopes). Others save themselves by hiding. Many offer resistance in the shape of a specialised protective covering (a prickly skin, a stiff coat of mail). Not a few Insects are characterised by a repulsive taste or odour, and by this keep the enemy at a distance; many animals are protected, whether in motion or at rest, by their resemblance to their sur- roundings (protective resemblance) ; many, on account of their green colour, are difficult to distinguish from their food-plant; many, again, are concealed by the leaf-like appearance of the wings or other parts : the most delusive resemblance is perhaps found in some Indian diurnal Butterflies (Kallima) which can scarcely be distinguished. Pig. 43. Two specimens of a Kallima settled, with closed wings, between withered leaves.—After Wallace. Fig. 44. Two looper oaterpillers (Qeo- meira betularia). from the dry leaves of the trees or shrubs whereon they rest with folded wings. Among European Lepidoptera, a Bombyx (Gastropacha quercifolia) also exhibits a remarkable similarity to dry leaves. Other Insects are like withered twigs, some Looper-caterpillars (Fig. 44), which extend motionless from a branch, attached only by the hinder end. It seems specially remarkable that some animals which are protectively modified have come to resemble, externally, others which are from some cause unpleasant to their enemies, and therefore, are comparatively unmolested (mimicry). In South America, for instance, there lives a group of Butterflies (the Heli- conidse), poor fliers, with conspicuous colouring but with so unpleasant a smell, that they are rejected by Birds; certain other Butterflies, living with these, but not posses
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