What natural force could possibly have produced such abnormal and extraordinary plants? What must have been the aspect of the globe, during the first centuries of its formation, when under the combined action of heat and humidity, the vegetable kingdom occupied its vast surface to the exclusion of everything else?

These were considerations of never-ending interest for the geologist and the philosopher.

All this while we were advancing on our journey; and at length night came; but as I had remarked the evening before, the luminous state of the atmosphere was in nothing diminished. Whatever was the cause, it was a phenomenon upon the duration of which we could calculate with certainty.

As soon as our supper had been disposed of, and some little speculative conversation indulged in, I stretched myself at the foot of the mast, and presently went to sleep.

Hans remained motionless at the tiller, allowing the raft to rise and fall on the waves. The wind being aft, and the sail square, all he had to do was to keep his oar in the centre.

Ever since we had taken our departure from the newly named Port Gretchen, my worthy uncle had directed me to keep a regular log of our day's navigation, with instructions to put down even the most minute particulars, every interesting and curious phenomenon, the direction of the wind, our rate of sailing, the distance we went; in a word, every incident of our extraordinary voyage.

From our log, therefore, I tell the story of our voyage on the Central Sea.

Friday, August 14th. A steady breeze from the northwest. Raft progressing with extreme rapidity, and going perfectly straight. Coast still dimly visible about thirty leagues to leeward. Nothing to be seen beyond the horizon in front. The extraordinary intensity of the light neither increases nor diminishes. It is singularly stationary. The weather remarkably fine; that is to say, the clouds have ascended very high, and are light and fleecy, and surrounded by an atmosphere resembling silver in fusion.

Thermometer, +32 degrees centigrade.

About twelve o'clock in the day our guide Hans having prepared and baited a hook, cast his line into the subterranean waters. The bait he used was a small piece of meat, by means of which he concealed his hook. Anxious as I was, I was for a long time doomed to disappointment. Were these waters supplied with fish or not? That was the important question. No--was my decided answer. Then there came a sudden and rather hard tug. Hans coolly drew it in, and with it a fish, which struggled violently to escape.

"A fish!" cried my uncle.

"It is a sturgeon!" I cried, "certainly a small sturgeon."

The Professor examined the fish carefully, noting every characteristic; and he did not coincide in my opinion. The fish had a flat head, round body, and the lower extremities covered with bony scales; its mouth was wholly without teeth, the pectoral fins, which were highly developed, sprouted direct from the body, which properly speaking had no tail. The animal certainly belonged to the order in which naturalists class the sturgeon, but it differed from that fish in many essential particulars.

My uncle, after all, was not mistaken. After a long and patient examination, he said:

"This fish, my dear boy, belongs to a family which has been extinct for ages, and of which no trace has ever been found on earth, except fossil remains in the Devonian strata."

"You do not mean to say," I cried, "that we have captured a live specimen of a fish belonging to the primitive stock that existed before the deluge?"

"We have," said the Professor, who all this time was continuing his observations, "and you may see by careful examination that these fossil fish have no identity with existing species. To hold in one's hand, therefore, a living specimen of the order, is enough to make a naturalist happy for life."

"But," cried I, "to what family does it belong?"

"To the order of Ganoides--an order of fish having angular scales, covered with bright enamel--forming one of the family of the Cephalaspides, of the genus--"

"Well, sir," I remarked, as I noticed my uncle hesitated to conclude.

"To the genus Pterychtis--yes, I am certain of it. Still, though I am confident of the correctness of my surmise, this fish offers to our notice a remarkable peculiarity, never known to exist in any other fish but those which are the natives of subterranean waters, wells, lakes, in caverns, and suchlike hidden pools."

"And what may that be?"

"It is blind."

"Blind!" I cried, much surprised.

"Not only blind," continued the Professor, "but absolutely without organs of sight."

I now examined our discovery for myself. It was singular, to be sure, but it was really a fact. This, however, might be a solitary instance, I suggested. The hook was baited again and once more thrown into the water. This subterranean ocean must have been tolerably well supplied with fish, for in two hours we took a large number of Pterychtis, as well as other fish belonging to another supposed extinct family--the Dipterides (a genus of fish, furnished with two fins only, whence the name), though my uncle could not class it exactly. All, without exception, however, were blind. This unexpected capture enabled us to renew our stock of provisions in a very satisfactory way.

We were now convinced that this subterranean sea contained only fish known to us as fossil specimens--and fish and reptiles alike were all the more perfect the farther back they dated their origin.

We began to hope that we should find some of those saurians which science has succeeded in reconstructing from bits of bone or cartilage.

I took up the telescope and carefully examined the horizon--looked over the whole sea; it was utterly and entirely deserted. Doubtless we were still too near the coast.

After an examination of the ocean, I looked upward, towards the strange and mysterious sky. Why should not one of the birds reconstructed by the immortal Cuvier flap his stupendous wings aloft in the dull strata of subterranean air? It would, of course, find quite sufficient food from the fish in the sea. I gazed for some time upon the void above. It was as silent and as deserted as the shores we had but lately left.

Nevertheless, though I could neither see nor discover anything, my imagination carried me away into wild hypotheses. I was in a kind of waking dream. I thought I saw on the surface of the water those enormous antediluvian turtles as big as floating islands. Upon those dull and somber shores passed a spectral row of the mammifers of early days, the great Liptotherium found in the cavernous hollow of the Brazilian hills, the Mesicotherium, a native of the glacial regions of Siberia.

Farther on, the pachydermatous Lophrodon, that gigantic tapir, which concealed itself behind rocks, ready to do battle for its prey with the Anoplotherium, a singular animal partaking of the nature of the rhinoceros, the horse, the hippopotamus and the camel.

There was the giant Mastodon, twisting and turning his horrid trunk, with which he crushed the rocks of the shore to powder, while the Megatherium--his back raised like a cat in a passion, his enormous claws stretched out, dug into the earth for food, at the same time that he awoke the sonorous echoes of the whole place with his terrible roar.

Higher up still, the first monkey ever seen on the face of the globe clambered, gamboling and playing up the granite hills. Still farther away, ran the Pterodactyl, with the winged hand, gliding or rather sailing through the dense and compressed air like a huge bat.

Above all, near the leaden granitic sky, were immense birds, more powerful than the cassowary and the ostrich, which spread their mighty wings and fluttered against the huge stone vault of the inland sea.

I thought, such was the effect of my imagination, that I saw this whole tribe of antediluvian creatures. I carried myself back to far ages, long before man existed--when, in fact, the earth was in too imperfect a state for him to live upon it.

My dream was of countless ages before the existence of man. The mammifers first disappeared, then the mighty birds, then the reptiles of the secondary period, presently the fish, the crustacea, the mollusks, and finally the vertebrata. The zoophytes of the period of transition in their turn sank into annihilation.