In the tropical zone, where the prodigality of life multiplies the enemies which every creature has to encounter, we may naturally expect to find the insects extremely well provided with both passive and active means of defence. Many so closely resemble in colour the soil or object on which they are generally found, as to escape even the eye of a hungry enemy. The wings of several Brazilian moths appear like withered leaves that have been gnawed round their margins by insects; and when these moths are disturbed, instead of flying away, they fall upon the ground like the leaf which they resemble, so that it is difficult, if not impossible, on such occasions to know what they really are. [Illustration: PHYLLIUM.] The illusion is still more complete when the likeness of form is joined to that of colour, as in the walking-leaf and walking-stick insects. Some, of an enormous length, look so exactly like slender dead twigs covered with bark, that their insect nature can only be discovered by mere accident--upon being handled they feign death, and their legs are often knobbed, like the withered buds of trees; some resemble living twigs, and are green; others such as are decayed, and are therefore coloured brown; the wings of many put on the resemblance of dry and crumpled leaves, while those of others are vivid green-- in exact accordance with the plants they respectively inhabit. This highly remarkable family consists of the herbivorous Phasmas and Phylliums--the former of which have a thin twig-like shape, while the latter have an enlarged body--and of the carniverous Mantides, or soothsayers. As the Mantis is slow and without much muscular energy, and its organisation requires a large supply of food, Nature has disguised it under the form of a plant, the better to deceive its victims. Like a cat approaching a mouse, it moves almost imperceptibly along, and steals towards its prey, fearful of putting it to flight. When sufficiently near, the fore legs are suddenly darted out to their full length, and seize the doomed insect, which vainly endeavours to extricate itself; the formation of the fore leg enabling the tibia to be so closed on the sharp edge of the thigh as to amputate any slender substance brought within its grasp, and to make even an entomologist repent a too hasty seizure of his prize. The Mantis, by the attitude it assumes when lurking for its prey or advancing upon it--which is done by the support of the four posterior legs only, whilst the head and prothorax are raised perpendicularly from the body, and the anterior legs are folded in front--greatly resembles a person praying. Hence, in France it is called Le Prêcheur, or Le Prie Dieu; the Turk says it points to Mecca; and several African tribes pay it religious observances. In reality, however, its ferocity is great, and the stronger preying on the weaker of their own species, unmercifully cut them to pieces. [Illustration: MANTIS.]