As is usual in tropical climates, a blazing hot day was succeeded by an intensely dark night.  The fire that the hunters had made on shore cast a lurid glare on the prominent objects round about.  The flames, as they fitfully lit up the landscape into that dim distinctness termed by artists the chiar oscuro, made the bushes and trunks of trees appear like monsters issuing stealthily from the forest that lined the background.  There seemed to be some attraction, however, elsewhere for the real monsters, not a single wild beast having as yet appeared on the scene.

The two young men were eagerly straining their eyes from the stern of the pinnace, whilst the dogs kept diligently wagging their tails in expectation of a signal for the onset.  The position of Willis could be ascertained now and then by an eye of fire, which opened and shut as he inhaled or exhaled the fumes of his Maryland.  The ripple beat gently on the sea-line of the boat, which oscillated with the regularity and softness of a cradle.

“It is always so,” said Jack, impatiently; “if we don’t want wild beasts, there are shoals of them to be seen; but if we do want them, then they are all off to their dens.”

“Perhaps, there are none now,” suggested Willis.

“Say rather,” observed Fritz, “that there ought to be thousands; for on the one hand they multiply rapidly, and on the other there is no one to destroy them.  Spaniards once left a few cattle on St. Domingo, and they increased at such a rate, that the island very soon would not have been able to support them, had they not been kept down by constant slaughter.”

“Besides,” remarked Jack, “the bovine race reproduce themselves more slowly than other animals; a single sow, according to a calculation made by Vauban, if allowed to live eleven years, would produce six millions of pigs.”

“What a cargo of legs of pork and sides of bacon!” exclaimed Willis, laughing.

“Then fish; there are more than a hundred and sixty thousand eggs in a single carp.  A sturgeon contains a million four hundred and sixty-seven thousand eight hundred and fifty, whilst in some codfish the number exceeds nine millions.”

“Oh, you need not favor us with the ‘Mariner’s March,’ Willis; what my brother says is perfectly correct.”

“What, then, do these shoals of creatures live upon?”

“The big ones upon the little ones; fish devour each other.”

“A beautiful harmony of Nature,” remarked Fritz drily.

“Then plants,” continued Jack, “are still more prolific than animals.  Some trees can produce as many of their kind as they have branches, or even leaves.  An elm tree, twelve years old, yields sometimes five hundred thousand pods; and, by the way, Willis, to encourage you in carrying on the war against the mosquitoes, a single stalk of tobacco produces four thousand seeds.”

“The leaves, however, are of more use to me than the seeds,” replied Willis.