Lucien had run on in front with the two partridges; when I arrived at the bivouac, I found an enormous mole roasting on the fire, and Sumichrast catching with the utmost care the fat which ran from it.

"How did you kill this animal?" I asked, addressing my companions; "I did not hear you fire."

"L'Encuerado knocked it down with the butt-end of his gun, and just at the same moment your two shots brought us back to the cave."

"Why are you collecting this fat? Is it a prophet of some new dish in preparation?"

"No; but I intend inspecting the cave, and with this grease we shall be able to make a lamp, which will be more than useful."

I approved of Sumichrast's idea, and, as he had discovered a colony of moles, proposed to go after dinner and catch some of them, so as to increase our supply of light. Besides, I hoped that in this walk we should meet with some kind of resinous tree, the branches of which might serve as torches. Lucien could hardly restrain his joy, and wished to penetrate into the cave without further delay. He scarcely gave himself time enough to eat, and scolded l'Encuerado for being so slow, which was an indirect mode of asking us to hurry.

Having again reached the forest, we searched for a pine or a fir, the branches of which, being full of resin, would have enabled us to show more mercy to the moles. Hearing us mention these two trees, Lucien wanted to know the difference between them.

"They both belong to the Coniferous family," replied Sumichrast; "but firs generally grow upon lofty mountains far inland, while pines abound on sea-coasts, the shifting, sandy soil of which is, after a time, consolidated and fertilized by them."

Sumichrast's explanation still left much wanting; I saw this from Lucien's numerous questions; but without seeing a specimen of each tree it would have been difficult to better describe their peculiar characteristics.

After a long and unsuccessful walk, we halted in front of a guaiac-tree with dark-green foliage, a higher tree than any we had before met with. This fine member of the Rutacean family was covered with pale-blue flowers. It produces a gum used especially by the English in the preparation of tooth-powder; but the hardness of its wood, which would have blunted our weapons, induced me to pass it by. A little farther on, l'Encuerado spied out a liquid-amber tree, valuable on account of the balsam that oozes from its branches when cut, which is burned by the Indians as incense. He climbed the knotty trunk of this colossus, and cut off some branches, which Sumichrast split into small pieces, after I had cleared off their leaves. Our work was interrupted by the approach of night, and we made our way to our bivouac, each loaded with a heavy fagot.

As soon as we arrived, Lucien had the satisfaction of trying one of our flambeaux. The branch crackled when lighted, and, as we entered the cavern, five or six bats flew out. I led Lucien by the hand, and very soon he was the only one who could stand upright. Afterwards we entered a vast chamber with a dome-shaped roof, which became lower the farther we penetrated; this was rather a disappointment, as we had fancied there was something more to be seen than a mere cave. A heap of reddish earth in one corner attracted Sumichrast's attention, who examined it to see if he could discover some fossil bones. Standing all together, we must have formed, by the smoky light of our odoriferous torches, rather a fantastic-looking group. More than half an hour elapsed without discovering any results from our digging. L'Encuerado, who had tried to crawl in between the roof and the ground, suddenly raised an exclamation; he had, in fact, all but fallen into a deep pit. In an instant I was laid down flat on my stomach and crawling towards the Indian; Lucien, owing to his size, was able to creep on his hands and feet, and consequently soon got in front of me. We could soon see down into the bottom of the hole; the burning fragments of our torches fell upon a heap of stones at a depth of twelve or fifteen feet. L'Encuerado threw one of the torches into the chasm, and the vague glimmer showed us a yawning opening on the left. Delighted with this discovery, we now beat a retreat, deferring a more thorough exploration until the next day.

The night was dark, and during our absence the fire had almost gone out. Just below us, a tree, the outline of which we could scarcely distinguish, seemed covered with animated sparks. Lucien opened his eyes very widely indeed, not being in the least able to understand this phenomenon, which was produced by thousands of elaterides, insects which have on each side of the thorax a yellowish spot which becomes luminous in the dark.

Nothing could be more curious than to see innumerable glittering spots rising, falling, and crossing one another with extraordinary rapidity; one might have fancied it a tree bearing flowers of fire waving about in the breeze. L'Encuerado came up with a specimen, which lighted up his hand with a greenish glimmer. Lucien took possession of it, and the two luminous spots looked to him like two enormous eyes. Suddenly the insect gave a kind of shock to the boy's fingers, who looked at us full of surprise.

"The name of the insect," said Sumichrast, "is derived from a Greek word which signifies elastic; and it has just shown you that it well deserves the family name which has been given to it. Examine for an instant how it is shaped; the angles of its corslet form sharp points; added to this, its sternum also terminates in a point which the insect can insert at will into the cavity which exists under its second pair of legs. The women in the Terre-Chaude, by passing a pin through this natural ring, can fix this brilliant insect as an ornament in their hair, without injuring it in the least. Now, then, place it on its back."

"It's pretending to be dead!" cried Lucien.

"Yes; it does that, like many other kinds of insects, in order to deceive an enemy about to seize it."

"Oh, how it jumps!" exclaimed Lucien.

"That is its only means of getting on its feet again, when it has had the misfortune of falling on its back. Look; it pushes the point which terminates its chest against the edge of the hole situated lower down; then it raises its head, piff! paff! you might fancy it was a spring going off. It didn't succeed the first time, but now it is up on its legs, and now you've lost it, for it has flown off!"

Lucien's first impulse was to dart off in pursuit of it, as the route it had taken was shown by its luminous appendages. But it was long past our usual hour for repose, so we all sheltered ourselves as well as we could, and dreamt of our next day's adventures.

Day-break found us all up, and already comforted with a cup of coffee. We had been troubled during the night by mosquitoes; but they were only the harbingers of the legions which are before us. Lucien, full of impatience, could not take his eyes off the entrance of the cave, and followed all our movements with anxiety. A hollow stone which l'Encuerado had found was filled with fat, a morsel of linen served as a wick, and our make-shift lamp soon burned and gave forth light.

As the branches which were to serve as torches were being distributed, I noticed that a yellow and transparent drop had formed at the end of each. This gum, by its odor and color, has given to the tree which produces it the name of liquid amber. At last, followed by my companions, I entered the cave; l'Encuerado placed the lamp on the edge of the pit, and the bats which had been disturbed the evening before again commenced their whirling flight.

Preceded by Sumichrast, I ventured down to the bottom of the pit. A narrow passage led from it into a vast chamber, the more distant parts of which we could not discern on account of the darkness. While my friend was exploring, I returned for Lucien. The lamp, thanks to the Indian's skill, was safely let down without extinguishing the light; lastly l'Encuerado himself made his appearance. Passing along the narrow passage, I soon perceived Sumichrast, who looked like some fantastic apparition as he shook his torch over his head, endeavoring to see through the darkness which enveloped us.

The lamp being set down at the entrance of the passage, each of us took a lighted torch, and advanced at a slow pace. Sumichrast and the Indian skirted the wall to the left, while I walked along the wall to the right. Our smoky torches gave but an imperfect light, and we could scarcely see beyond three yards in front of us. A little farther on, the ground was strewn with fallen stones; before venturing on this dangerous ground, I cast a glance towards my companions; they were not in sight. I gave them a call—a formidable clamor resounded through the chamber, and Lucien crept close to me.

"It is the echo returning to our ears Sumichrast's answer," I hastened to tell him. "They are in another chamber; you call them now!"

The boy, agitated, raised his voice. Immediately the dark vaults seemed to repeat his words; and the sound increased, as it moved away, as if a thousand persons, placed at intervals, were repeating some watch-word. A sonorous "Hiou! hiou!" prevailed over the uproar, and the face of l'Encuerado appeared on our right before the echo of the call had died away.

"Come and see a beautiful church!" cried the Indian. "A church made of diamonds, Chanito!"

We moved towards the entrance by an inclined passage, down the slope of which we followed l'Encuerado. The distance between the walls gradually increased, and soon we found ourselves in a vast hall studded with stalactites; in it Sumichrast arranged the lighted torches.

The Indian was not far wrong; we might easily have fancied ourselves in a Gothic cathedral. The wildest dreams could not picture a stranger, more original, or more fantastic style of architecture. Never did any painter of fairy scenes imagine any effects more splendid. Hundreds of columns hung down from the roof and reached the ground below. It was a really wonderful assemblage of pointed arches, lace-work, branchery, and gigantic flowers. Here and there were statues drawn by nature's hand. Lucien particularly remarked a woman covered with a long veil, and stretching out over our heads an arm which a sculptor's chisel could scarcely have rendered more life-like. There were also shapeless mouths, monstrous heads, and animals, appearing as if they had been petrified, in menacing attitudes. The illusion was rendered more or less complete according to the play of the light; and many a strange shape was but caught sight of for a moment, to as rapidly vanish.

While we were moving about the cave, some long needles, hanging from the roof, touched our heads.

"They are stalactites," said I to the astonished Lucien. "The rain-water, filtering through the mountain above, dissolves the calcareous matter it meets with, and produces, when it evaporates, the beautiful concretions you are now looking at."

"Here is a needle coming up from the ground."

"That is a stalagmite; it increases upward, and not downward like the stalactites, through which, besides, a tube passes. Look up at that beautiful needle, with a drop of water glittering at the end of it. That liquid pearl, which has already deposited on the stalactite a thin layer of lime, will fall down on the stalagmite, the top of which is rounded. After a time the two needles will join, adding another column to the grotto, which, in the course of time, will become filled up with them."

"Then do stones proceed from water?" asked Lucien, with a thoughtful air.

"To a certain extent," I replied; "water holds in solution calcareous matter, and, as soon as the liquid evaporates, stone is formed."

"According to this," interposed l'Encuerado, "the pebbles ought to melt in the rivers."

"So they do; but they do not melt so easily as some things—sugar, for instance. Don't you recollect that in the Rio Blanco the water is almost like milk, and that it leaves a whitish coating on the branches, and even on the leaves with which it comes in contact."

"That's true enough," replied the Indian, who had often wondered at the petrifactions with which the banks of the White River abound.

"But the water that falls down here is quite clear," urged Lucien, holding his torch close to a natural basin.

"But, nevertheless, it contains salts of lime in solution, the same, in fact, as all water, particularly that from wells. And it is for this reason that housekeepers will not use it; for it will not dissolve soap, and hardens the vegetables that are cooked in it."

"Now do you understand this?" asked l'Encuerado, addressing Lucien; "I don't."

"Yes, I do, a little."

"Well, you are very fortunate! The other day stones were said to come from the sun or moon, and fly about all covered with fire; now, they are formed by water. Perhaps M. Sumichrast will tell us to-morrow that they come from the wind."

The Indian then walked away, quite indignant; we followed him, smiling at his anger, becoming more and more enchanted by the spectacle which met our eyes. Unfortunately, our torches gave a very insufficient light, and the thick smoke rapidly blackened the arches above us. A great polished stone now impeded our passage, and compelled us to crawl. I took the lead, and, passing through a kind of narrow corridor, made my way into a small chamber. I raised a sudden exclamation; for five or six skulls, symmetrically arranged, seemed to glare at me through their empty orbits.

"Oh father!" cried Lucien, "are we in a cemetery?"

"Yes, my boy; I think this must be a Chichimec burial-place. This nation, which preceded the Toltecs and Aztecs in Mexico, were in the habit of depositing their dead in caverns."

Sumichrast examined a skull which he had picked up; its white and perfect teeth showed that it must have belonged to a man who died young. A few paces farther on five or six more skulls lay on the surface of the ground; they were inclosed in by fine stalactites, and appeared as if they were grinning at us through the bars of a dungeon.

For more than a thousand years, perhaps, these skulls had reposed in the niches which had evidently been hollowed out on purpose for them. The soil of the grotto had apparently risen at a subsequent period. What revelations as to the ancient history of Mexico might be contained in this cave! Without much difficulty, l'Encuerado broke through the upper calcareous layer, and brought to light some loamy earth, out of which he procured a small cup of baked clay. I then began digging; my fingers soon touched some hard object; it was a small stone statuette. I had scarcely loosened my discovery from the earth, before Lucien also plunged his arm into the hole and brought out a little fancifully-shaped tortoise, the tail of which had been used as a whistle. Enticed on by these successes, we knelt down so as to break through a wider extent of the calcareous stratum; but our torches began to burn palely, and the close chamber, now filled with a thick smoke, was no longer bearable. Sumichrast complained of humming in his ears, and I also felt uncomfortable; so, much against our inclination, I gave the signal of departure. The lamp was dying out, and was filling the outer chamber with a nasty smell, which gave the finishing-stroke to our unpleasant feelings. L'Encuerado and Lucien were the first to leave the cave; from it I afterwards emerged with Sumichrast, both being quite blinded, when we reached the open air, by the overpowering rays of the sun.

Shouts of laughter resounded on all sides; we had the appearance of negroes, or rather of chimney-sweeps. It was no use thinking about washing ourselves; the contents of our gourds were too precious; and besides, there would not have been water sufficient. As there was water in the cave, l'Encuerado offered to go in and fetch some; but the smoke which escaped from the hole made me feel anxious, so, for the time, I opposed the Indian's re-descending into it.

We were surprised at the time our exploration had lasted; it had taken no less than four hours. Although we had made up our minds to continue our journey on coming out of the cavern, the fatigue we felt, added to a desire to have another look at the subterranean wonders, decided us to put off our departure until the next day.

After resting an hour, we all set off to seek our dinner. I examined with much curiosity the neighborhood of our encampment. The presence of skulls in the cave proved that some Indian tribe had once inhabited this locality; but as the Chichimec (or Chichiquimec, in the chapter-heading) Indians constructed nothing but huts, time had, doubtless, obliterated all trace of their former presence.

I can hardly describe the pleasure I felt in again viewing the woods, the verdure, the insects, the flowers, and enjoying the light of the sun. The interior of a cave, certainly, has the effect of producing melancholy, attributable, no doubt, to the silence and darkness; for the beautiful hall, radiant with stalactites, was but little likely to cause sadness. The effect on Lucien's mind was of a serious character, and he seemed never to be weary of asking questions.

"These natural hollows," said Sumichrast, "often occur in gypsum mountains, but still more frequently in volcanic or calcareous masses. Some, which are as old as the world itself, date from the earliest upheavals of the surface of the globe, when the fused matter which composes the centre of the earth broke through the scarcely solidified crust, and, rushing upward, formed the mountain chains we now see."

"Then the centre of the earth has been once in a liquid state?"

"It is so still, as is shown by volcanoes; but the period of great catastrophes is past. The molten matter solidified on the surface, as it became cool, and then water made its appearance, and transformed and rendered habitable the thin crust on which we live, the thickness of which is so inconsiderable when compared with the bulk of the globe."

"What is this molten matter composed of which is burning under our feet?"

"The same substances which we see around us—granite, porphyry, and basalts, which are called igneous or Vulcanian rocks, as contrasted with the Neptunean rocks, such as gypsum or lime, clay and sandstone, the agglomeration of which is attributed to water. The science which deals with these subjects is called geology, a study with which, some day, you will be delighted."

"Then all Vulcanian rocks can be melted?"

"Yes, if they were subject to as great a heat as that existing in the centre of the earth, which reaches an intensity at which the imagination recoils. But to return to the subject of caves. Some have been produced by the dissolving action of water. Thus, at some future date, the spring which we saw gushing out from the fallen mountain might dry up or alter its direction, and leave for the curiosity of future travellers the sight of chambers full of stalactites such as we have inspected."

Our geological chat was interrupted by an exclamation from l'Encuerado, who had just discovered a tree which the Mexicans call "the Tree of St. Ignatius." Its fruit is of a brown color, with a woody husk, something like small melons, which, as they hang on the tree, strike against one another with a sharp sound. L'Encuerado informed Lucien that this fruit is in the habit of bursting suddenly with a loud explosion, and that the flat beans which they contain are much used as medicine.

Sumichrast led the way through the forest, where we were sheltered under the tall trees. After a somewhat long ramble, during which we met with nothing but magpies, I requested l'Encuerado to guide us back to our bivouac. All of a sudden my friend enjoined silence; an opossum, followed by five young ones, was coming near us on our left. The animal indolently approached a tree of middling size, which it climbed, aided by its prehensile tail. Its progeny crowded busily round the foot of the tree, uttering plaintive cries. The opossum then came down again, and scarcely had it put foot to the ground before its disconsolate family rushed pell-mell into the maternal pouch. Thus loaded, the animal climbed the tree more slowly, and sat herself quietly on one of the lowest branches. We could see nothing but the pointed muzzles and black eyes of the little ones, which seemed as if they were looking down from the top of a balcony. One of them at last ventured to emerge, and crawled along the branches; soon the whole litter followed this example. Sumichrast advised Lucien to clap his hands, and I ordered l'Encuerado not to fire at the poor animal. Frightened at the noise, the little ones hastened to their mother, who set up her thin ears and showed us a double row of white teeth. One of the stupid little things, in its haste to reach its asylum, fell down from the tree. In a moment the opossum had jumped down close to it, and turned towards us her threatening jaws; then, finding all her treasure complete, she disappeared among the brush-wood.

"Why didn't you let me shoot at the tlacuache?" asked l'Encuerado.

"What is the good of killing a poor creature which would be of no use to us?"

"You know well enough," replied the Indian, "that this 'poor beast' finds its way into granaries; that it devours the corn and also fowls, without reckoning the damage made by them in other ways."

"Yes, that's true enough; but this animal, at least, is innocent of all these misdeeds, for it lives too far from any town."

This scene had quite delighted Lucien. I acquainted him with the fact that opossums, kangaroos, and several other animals of the kind, the females of which are provided with a pouch to shelter the young ones, are, for this reason, called marsupials.

The opossum is very common in Mexico. Its long, pointed, and deeply-divided muzzle is armed with fifty-two formidable teeth, although the animal feeds principally on eggs, insects, and birds. The young of those species which are unprovided with the pouch, as soon as they are able to walk, climb up on their mother's back and intertwine their tails with hers, which she carries over her back for this purpose. This instinct is perhaps more curious than that which leads them to dart into their mother's protecting pouch.

Time was getting on; it now became important for us to reach the spot where the moles were; and l'Encuerado predicted good sport there without firing off his gun.