extraordinary bird to the passeres, the genera of which are connected with each other by almost imperceptible transitions. It forms a new genus, very different from the goatsucker, in the loudness of its voice, in the vast strength of its beak (containing a double tooth), and in its feet without the membranes which unite the anterior phalanges of the claws. It is the first example of a nocturnal bird among the Passeres dentirostrati. Its habits present analogies both with those of the goatsuckers and of the alpine crow.* (* Corvus Pyrrhocorax.) The plumage of the guacharo is of a dark bluish grey, mixed with small streaks and specks of black. Large white spots of the form of a heart, and bordered with black, mark the head, wings, and tail. The eyes of the bird, which are dazzled by the light of day, are blue, and smaller than those of the goatsucker. The spread of the wings, which are composed of seventeen or eighteen quill feathers, is three feet and a half. The guacharo quits the cavern at nightfall, especially when the moon shines. It is almost the only frugiferous nocturnal bird yet known; the conformation of its feet sufficiently shows that it does not hunt like our owls. It feeds on very hard fruits, like the nutcracker* (* Corvus caryocatactes, C. glandarius. Our Alpine crow builds its nest near the top of Mount Libanus, in subterranean caverns, nearly like the guacharo. It also has the horribly shrill cry of the latter.) and the pyrrhocorax. The latter nestles also in clefts of rocks, and is known by the name of the night-crow. The Indians assured us that the guacharo does not pursue either the lamellicornous insects or those phalaenae which serve as food to the goatsuckers. A comparison of the beaks of the guacharo and the goatsucker serves to denote how much their habits must differ. It would be difficult to form an idea of the horrible noise occasioned by thousands of these birds in the dark part of the cavern. Their shrill and piercing cries strike upon the vaults of the rocks, and are repeated by the subterranean echoes. The Indians showed us the nests of the guacharos by fixing a torch to the end of a long pole. These nests were fifty or sixty feet high above our heads, in holes in the shape of funnels, with which the roof of the grotto is pierced like a sieve. The noise increased as we advanced, and the birds were scared by the light of the torches of copal. When this noise ceased a few minutes around us, we heard at a distance the plaintive cries of the birds roosting in other ramifications of the cavern. It seemed as if different groups answered each other alternately.

The Indians enter the Cueva del Guacharo 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,* (* Called Los pollos del Guacharo.) 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 anus, forming a kind of cushion between the legs of the bird. This quantity of fat in frugivorous animals, not exposed to the light, and exerting very little muscular motion, reminds us of what has been observed in the fattening of geese and oxen. It is well known how greatly darkness and repose favour this process. The nocturnal birds of Europe are lean, because, instead of feeding on fruits, like the guacharo, they live on the scanty produce of their prey. At the period commonly called, at Caripe, the oil harvest,* (* La cosecha de la manteca.) the Indians build huts with palm-leaves, near the entrance, and even in the porch of the cavern. There, 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 (manteca, or aceite) of the guacharo. 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.

The race of the guacharos would have been long ago extinct, had not several circumstances contributed to its preservation. The natives, restrained by their superstitious ideas, seldom have courage to penetrate far into the grotto. It appears also, that birds of the same species dwell in neighbouring caverns, which are too narrow to be accessible to man. Perhaps the great cavern is repeopled by colonies which forsake the small grottoes; for the missionaries assured us that hitherto no sensible diminution of the birds has been observed. Young guacharos have been sent to the port of Cumana, and have lived there several days without taking any nourishment, the seeds offered to them not suiting their taste. When the crops and gizzards of the young birds are opened in the cavern, they are found to contain all sorts of hard and dry fruits, which furnish, under the singular name of guacharo seed (semilla del guacharo), a very celebrated remedy against intermittent fevers. The old birds carry these seeds to their young. They are carefully collected, and sent to the sick at Cariaco, and other places of the low regions, where fevers are generally prevalent.

As we continued to advance into the cavern, we followed the banks of the small river which issues from it, and is from twenty-eight to thirty feet wide. We walked on the banks, as far as the hills formed of calcareous incrustations permitted us. Where the torrent winds among very high masses of stalactites, we were often obliged to descend into its bed, which is only two feet deep. We learned with surprise, that this subterranean rivulet is the origin of the river Caripe, which, at the distance of a few leagues, where it joins the small river of Santa Maria, is navigable for canoes. It flows into the river Areo under the name of Cano do Terezen. We found on the banks of the subterranean rivulet a great quantity of palm-tree wood, the remains of trunks, on which the Indians climb to reach the nests hanging from the roofs of the cavern. The rings, formed by the vestiges of the old footstalks of the leaves, furnish as it were the steps of a ladder perpendicularly placed.

The Grotto of Caripe preserves the same direction, the same breadth, and its primitive height of sixty or seventy feet, to the distance of 472 metres, or 1458 feet, accurately measured. We had great difficulty in persuading the Indians to pass beyond the anterior portion of the grotto, the only part which they annually visit to collect the fat. The whole authority of 'los padres' was necessary to induce them to advance as far as the spot where the soil rises abruptly at an inclination of sixty degrees, and where the torrent forms a small subterranean cascade.* (* We find the phenomenon of a subterranean cascade, but on a much larger scale, in England, at Yordas Cave, near Kingsdale in Yorkshire.) The natives connect mystic ideas with this cave, inhabited by nocturnal birds; they believe that the souls of their ancestors sojourn in the deep recesses of the cavern. "Man," say they, "should avoid places which are enlightened neither by the sun (zis), nor by the moon (nuna)." 'To go and join the guacharos,' is with them a phrase signifying to rejoin their fathers, to die. The magicians (piaches) and the poisoners (imorons) perform their nocturnal tricks at the entrance of the cavern, to conjure the chief of the evil spirits (ivorokiamo). Thus in every region of the earth a resemblance may be traced in the early fictions of nations, those especially which relate to two principles governing the world, the abode of souls after death, the happiness of the virtuous and the punishment of the guilty. The most different and most barbarous languages present a certain number of images, which are the same, because they have their source in the nature of our intelligence and our sensations. Darkness is everywhere connected with the idea of death. The Grotto of Caripe is the Tartarus of the Greeks; and the guacharos, which hover over the rivulet, uttering plaintive cries, remind us of the Stygian birds.

At the point where the river forms the subterranean cascade, a hill covered with vegetation, which is opposite to the opening of the grotto, presents a very picturesque aspect. It is seen at the extremity of a straight passage, 240 toises in length. The stalactites descending from the roof, and resembling columns suspended in the air, are relieved on a back-ground of verdure. The opening of the cavern appeared singularly contracted, when we saw it about the middle of the day, illumined by the vivid light reflected at once from the sky, the plants, and the rocks. The distant light of day formed a strange contrast with the darkness which surrounded us in the vast cavern. We discharged our guns at a venture, wherever the cries of the nocturnal birds and the flapping of their wings, led us to suspect that a great number of nests were crowded together. After several fruitless attempts M. Bonpland succeeded in killing a couple of guacharos, which, dazzled by the light of the torches, seemed to pursue us. This circumstance afforded me the means of making a drawing of this bird, which had previously been unknown to naturalists. We climbed, not without difficulty, the small hill whence the subterranean rivulet descends. We saw that the grotto was perceptibly contracted, retaining only forty feet in height, and that it continued stretching to north-east, without deviating from its primitive direction, which is parallel to that of the great valley of Caripe.

In this part of the cavern, the rivulet deposits a blackish mould, very like the matter which, in the grotto of Muggendorf, in Franconia, is called "the earth of sacrifice."* (* Opfer-erde of the cavern of Hohle Berg (or Hole Mountain,--a mountain pierced entirely through.)) We could not discover whether this fine and spongy mould falls through the cracks which communicate with the surface of the ground above, or is washed down by the rain-water penetrating into the cavern. It was a mixture of silex, alumina, and vegetable detritus. We walked in thick mud to a spot where we beheld with astonishment the progress of subterranean vegetation. The seeds which the birds carry into the grotto to feed their young, spring up wherever they fix in the mould which covers the calcareous incrustations. Blanched stalks, with some half-formed leaves, had risen to the height of two feet. It was impossible to ascertain the species of these plants, their form, colour, and aspect having been changed by the absence of light. These traces of organization amidst darkness forcibly excited the curiosity of the natives, who examined them with silent meditation inspired by a place they seemed to dread. They evidently regarded these subterranean plants, pale and deformed, as phantoms banished from the face of the earth. To me the scene recalled one of the happiest periods of my early youth, a long abode in the mines of Freyberg, where I made experiments on the effects of blanching (etiolement), which are very different, according as the air is pure or overcharged with hydrogen or azote.

The missionaries, with all their authority, could not prevail on the Indians to penetrate farther into the cavern. As the roof became lower the cries of the guacharos were more and more shrill. We were obliged to yield to the pusillanimity of our guides, and trace back our steps. The appearance of the cavern was however very uniform. We found that a bishop of St. Thomas of Guiana had gone farther than ourselves. He had measured nearly 2500 feet from the mouth to the spot where he stopped, but the cavern extended still farther. The remembrance of this fact was preserved in the convent of Caripe, without the exact period being noted. The bishop had provided himself with great torches of white Castile wax. We had torches composed only of the bark of trees and native resin. The thick smoke which issued from these torches, in a narrow subterranean passage, hurts the eyes and obstructs the respiration.