There is another large lizard, known as the great dragon (Ada Guianensis). It is of an olive colour, with yellow below, and mottled with brown; and frequently attains a length of six feet. While the former cannot climb trees, it is a good swimmer. The great dragon climbs with wonderful agility, but is said not to be very much at home in the water. It also bites fiercely. Both are hunted for the sake of their flesh; while their eggs--of which thirty or forty are laid--are considered great delicacies. GECKOS. Not only in the huts of the natives, but in the abodes of the wealthy white men, hid during the day in dark corners, are numbers of dark grey, hideous-looking lizards, which, when night comes on, crawl rapidly over the walls and ceilings, hunting for the flies and other insects to be found there. Repulsive as are these little geckos, and undeservedly possessing a bad name for being poisonous, they are not only harmless, but render good service by the destruction of numerous household pests. Their large eyes are so constructed that they can discern objects in the dark, and are at the same time capable of bearing the rays of the bright sun. Their colour, too, enables them to escape detection by the creatures which attack them, while they are thus hid from the prey for which they lie in wait. They can also bend themselves in an extraordinary way into hollows and crevices. But their feet are especially curious, being admirably adapted for clinging to and running over smooth surfaces. The under side of their toes is expanded into cushions, beneath which folds of skin form a series of flexible plates. By means of this apparatus they can run or crawl across a smooth ceiling with their backs downwards--the soft soles, by quick, muscular action, exhausting and admitting air alternately. They are also provided with sharp claws, which enable them to climb up the trunks of trees, and over rough surfaces. The Brazilians call them osgas, and believe that they poison by their touch whatever they pass over. Probably, however, if any annoyance does arise from them, it is when with their sharp claws they run across a sleeping man, or small blisters have been raised by the adhering apparatus at the bottom of their feet. By some "the spider, which taketh hold with her hands," is believed to be a gecko, as a species of this creature is very common in the East. The popular prejudice against them causes the death of many a poor gecko, who, had he been allowed to live, would have rendered good service to his persecutors. Those in the houses are of small size; but others, existing in the forest, and living in the crevices of the trees, are of considerable magnitude. Their tails are easily struck off--the loss being, however, as is the case with other lizards, repaired by a new growth, though less perfect than the original member. THE ANACONDA.