The same line of argument might be used to explain the much greater variety in some classes of terrestrial animals than in others. The land has often been submerged in geological history, and the classes that were best fitted to escape the impending catastrophes would be most likely to preserve the varieties that had been developed. The atmosphere has always been continuous, and the animals that could use it as a highway had great advantages over those that could not, and so we find the slow-moving terrestrial mollusks few in number compared with the multitudinous hosts of strong-flying insects; similarly, the mammals are far outnumbered by the birds of the air, that can pass from island to island, and from country to country, unstopped by mighty rivers or wide arms of the sea. CHAPTER 19. Iguanas and lizards. Granada. Politics. Revolutions. Cacao cultivation. Masaya. The lake of Masaya. The volcano of Masaya. Origin of the lake basin. THE road passed along a sandy ridge only a little elevated above the waters of the lake, and the ground on both sides was submerged. As we travelled on we were often startled by hearing sudden plunges into the water not far from us, but our view was so obstructed by bushes that it was some time before we discovered the cause. At last we found that the noise was made by large iguana lizards, some of them three feet long, and very bulky, dropping from the branches of trees, on which they lay stretched, into the water. These iguanas are extremely ugly, but are said to be delicious eating, the Indians being very fond of them. The Carca Indians, who live in the forest seven miles from Santo Domingo, travel every year to the great lake to catch iguanas, which abound on the dry hills near it. They seize them as they lie on the branches of the trees, with a loop at the end of a long stick. They then break the middle toe of each foot, and tie the feet together, in pairs, by the broken toes, afterwards sewing up the mouth of the poor reptiles, and carrying them in this state back to their houses in the forest, where they are kept alive until required for food. The raccoon-like "pisoti" is also fond of them, but cannot so easily catch them. He has to climb every tree, and then, unless he can surprise them asleep, they drop from the branch to the ground and scuttle off to another tree. I once saw a solitary "pisoti" hunting for iguanas amongst some bushes near the lake where they were very numerous, but during the quarter of an hour that I watched him, he never caught one. It was like the game of "puss in the corner." He would ascend a small tree on which there were several; but down they would drop when he had nearly reached them, and rush off to another tree. Master "pisoti," however, seemed to take all his disappointments with the greatest coolness, and continued the pursuit unflaggingly. Doubtless experience had taught him that his perseverance would ultimately be rewarded: that sooner or later he would surprise a