But now the clouds are lowering; they divide into strata, end, gradually getting heavier, denser, and darker, at last veil the horizon in a blueish grey mist.  Towards the zenith they tower up in bright broad-spreading masses, and assume the appearance of gigantic mountains in the air.  All at once the sky is completely overcast, excepting that a few spots of deep blue still appear through the clouds.  The sun is hid, but the heat of the atmosphere is more oppressive.  The noontide is past; a cheerless melancholy gloom hangs heavily over nature.  Fast sink the spirits; for painful is the change to those who have witnessed the joyous animation of the morning.  The more active animals roam wildly about, seeking to allay the cravings of hunger and thirst; only the quiet and slothful, who have taken refuge in the forest, seem to have no apprehension of the dreadful crisis.  But it comes! it rushes on with rapid strides, and we shall certainly have it here.  The temperature is already lowered; the fierce and clashing gales tear up trees by the roots.  Dark and foaming billows swell the surface of the deeply agitated sea.  The roar of the river is surpassed by the sound of the wind, and the waters seem to flow silently into the ocean.  There the storm rages.  Twice, thrice, flashes of pale blue lightning traverse the clouds in rapid succession:  as often does the thunder roll in loud and prolonged claps through the firmament.  Drops of rain fall.  The plants begin to recover their natural freshness; it thunders again, and the thunder is followed, not by rain, but by torrents, which pour down from the convulsed sky.  The forest groans; the whizzing rustle of the waving leaves becomes a hollow murmuring sound, which at length resembles the distant roll of muffled drums.  Flowers are scatterd to and fro, leaves are stripped from the boughs, branches are torn from the stems, and massy trees are overthrown; the terrible hurricane ravishes all the remaining virgin charms of the levelled and devastated plants.  But wherefore regret their fate?  Have they not lived and bloomed?  Has not the Inga twisted together its already emptied stamens?  Have not the golden petals fallen from the fractified blossoms of the Baniser_ia_, and has not the fruit-loaded Arum yielded its faded spathe to the storm?  The terrors of this eventful hour fall heavily even on the animal world.  The feathered inhabitants of the woods are struck dumb, and flutter about in dismay on the ground; myriads of insects seek shelter under leaves and trunks of trees.  The wild Mammalia are tamed, and suspend their work of war and carnage; the cold-blooded Amphibia alone rejoice in the overwhelming deluge, and millions of snakes and frogs, which swarm in the flooded meadows, raise a chorus of hissing and croaking.  Streams of muddy water flow through the narrow paths of the forests into the river, or pour into the cracks and chasms of the soil.  The temperature continues to descend, and the clouds gradually empty themselves.