They have been gouged out, in every direction, by the furious tropic rains and tropic rain-torrents.

Had the rocks been stratified and tolerably horizontal, these rains would have cut them out into tablelands divided by deep gullies, such as may be seen in Abyssinia, and in certain parts of the western United States.

But these rocks are altogether amorphous and unstratified, and have been poured or spouted out as lumps, dykes, and sheets of lava, of every degree of hardness; so that the rain, in degrading them, has worn them, not into tables and ranges, but into innumerable cones.

And the process of degradation is still going on rapidly.

Though a cliff, or sheet of bare rock, is hardly visible among the glens, yet here and there a bright brown patch tells of a recent landslip; and the masses of debris and banks of shingle, backed by a pestilential little swamp at the mouth of each torrent, show how furious must be the downpour and down-roll before the force of a sudden flood, along so headlong an incline.
But in strange contrast with the ragged outline, and with the wild devastation of the rainy season, is the richness of the verdure which clothes the islands, up to their highest peaks, in what seems a coat of green fur; but when looked at through the glasses, proves to be, in most cases, gigantic timber.