PDF - Wallace Online

in ANIMAL LIFE IN THE TROPICAL FORESTS 303inhabit the tropics, and they probably increase in numberstowards the equator. A rich vegetation and a due proportionof moisture and sunshine seem favourable to them, asshown by their great abundance and their varied kinds atPara and in the Am islands places which are nearly theantipodes of each other, but which both enjoy the fine equatorialclimate in perfection, and are alike pre-eminent in thevariety and beauty of their insect life.Three peculiar forms of lizard may be mentioned asspecially characteristic of the American, African, and Asiatictropical zones respectively. The iguanas of South Americaare large, arboreal, herbivorous lizards of a beautiful greencolour, which renders them almost invisible when restingquietly among foliage. They are distinguished by theserrated back, deep dew-lap, and enormously long tail, andare one of the few kinds of lizards whose flesh is considereda delicacy. The chameleons of Africa are also arboreallizards, and they have the prehensile tail, which is moreusually found among American animals. They are excessivelyslow in their motions, and are protected by the wonderfulpower of changing their colour so as to assimilate it withthat of immediately surrounding objects. Like the majorityof lizards they are insectivorous, but they are said to beable to live for months without taking food. The dragonsor flying lizards of India and the larger Malay islands areperhaps the most curious and interesting of living reptiles,owing to their power of passing through the air by means ofwing-like membranes, which stretch along each side of thebody and are expanded by means of slender bony processesfrom the first six false ribs. These membranes are foldedup close to the body when not in use, and are then almostimperceptible but when; open they form a nearly circularweb, the upper surface of which is generally zoned with redor yellow in a highly ornamental manner. By means of thisparachute the animal can easily pass from one tree to anotherfor a distance of about thirty feet, descending at first, but as itapproaches its destination rising a little so to reach the treewith its head erect. They are very small, being usuallynot more than two or three inches long, exclusive of theslender tail ;and when the wings are expanded in the sun-