"The Cueva del Guachero, or Cave of the Guacheros," as described by Humboldt, "is a vast fissure, pierced in the vertical profile of a rock, facing towards the south; and the rocks which surmount the grotto are covered with trees of immense height; succulent plants and orchidaceæ rise in the driest clefts, and plants waving in the wind hang in festoons at the entrance. Within the cave vegetation continues to the distance of forty paces. Daylight penetrates far into the grotto, but when the light begins to fail the hoarse voices of the inhabitants become audible, and it would be difficult to form an idea of the horrible noise occasioned by thousands of these birds in the dark parts of the cavern. Their shrill and piercing cries strike upon the vaults in the rocks, and are repeated by the subterranean echoes. The Indians showed us the nests of the Guacheros by fixing a torch to a long pole; these nests were fifty or sixty feet above our heads, in holes of the shape of funnels, with which the roof of the grotto is pierced like a sieve. The noise increased as we advanced, the birds becoming scared by the torches we carried, but when the din somewhat abated, immediately around us we heard at a distance the plaintive cries of others at roost in the ramifications of the cavern. It seemed as if different groups answered each other alternately. The Indians enter the Cueva del Guachero once a year, near Midsummer. They go armed with poles, with which they destroy the greater part of the nests. At that season several thousand birds are killed; and the old ones, as if to defend their brood, hover over the heads of the Indians, uttering terrible cries. The young, which fall to the ground, are opened on the spot. Their peritoneum is found extremely loaded with fat, and a layer of fat reaches from the abdomen to the vent, forming a kind of fatty cushion between the legs. At the period commonly called at Caripe the "oil harvest," the Indians build huts with palm leaves near the entrance and even in the porch of the cavern, where, with a fire of brushwood, they melt in pots of clay the fat of the young birds just killed. This fat is known by the name of butter or oil (_mantece_ or _aceite_) of the Guachero; it is half liquid, transparent, without smell, and so pure that it may be kept above a year without becoming rancid. At the convent of Caripe no other oil is used in the kitchen of the monks but that of the cavern, and we never observed that it gave the aliments a disagreeable taste or smell."