"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."