alternately complaining to each other of the intruders. The nests of these birds are fixed fifty or sixty feet from the ground, in funnel-shaped holes, with which the cavern roof is pierced like a sieve. Armed with poles, the natives once a year, about mid-summer, enter the cavern and knock down the young birds, while the old ones, with lamentable cries, hover over the heads of the robbers. The young which are taken are opened on the spot, when the peritonaeum is found loaded with fat, and a layer of substance reaches from the abdomen to the vent, forming a kind of cushion between the bird's legs. At this period, called by the Indians the oil harvest, huts are erected by them, with palm leaves, near the entrance. Here the fat of the young birds is melted in clay pots, over a brushwood fire; but although thousands are killed, not more than 160 jars of clear oil are obtained. A small river flows through the cavern, and the visitor is compelled, as he proceeds, to wade through water, not, however, more than two feet deep. From the entrance as far as 1458 feet the cavern maintains the same direction, width, and height, after which it loses its regularity, and its walls are covered with stalactites. The same bird has been found in the province of Bogota, and may probably be discovered in other caverns. Animal life exists in considerable quantities in many subterranean regions, such as beetles, eyeless spiders, scorpions, millipedes, and crustaceans. The most curious is the Proteus anguinus, which breathes at the same time through lungs and gills. It has a long eel-like body, with an elongated head, and four very short and thin legs. The skin is flesh-coloured, and so translucent that the liver and heart, which beat about fifty times a minute, can be seen distinctly beneath. Two little black spots, resembling eyes, lie buried under the skin, and are only partially developed. Weak as it appears, it glides rapidly through the water, when its four little legs remain motionless; it uses them, indeed, only for creeping, and then in a very imperfect manner. Seven distinct species of proteus have been discovered, six of which were found in the cavern of Carniola, besides crickets, spiders, and a few crustaceae. A peculiar blind rat is found in the Mammoth Cave of Kentucky. A blind fish swims in its rivers, and Professor Agassiz is of opinion that they, like all other blind animals of the cavern world, have at no time been connected with the world of light.