intense. For nearly an hour we wandered about in this visible
darkness. At length I left the spot, and once more returned to the
shores of the lake, to light and comparative warmth.

But the amazing vegetation of subterraneous land was not confined to
gigantic mushrooms. New wonders awaited us at every step. We had not
gone many hundred yards, when we came upon a mighty group of other trees
with discolored leaves--the common humble trees of Mother Earth, of an
exorbitant and phenomenal size: lycopods a hundred feet high; flowering
ferns as tall as pines; gigantic grasses!

"Astonishing, magnificent, splendid!" cried my uncle; "here we have
before us the whole flora of the second period of the world, that of
transition. Behold the humble plants of our gardens, which in the first
ages of the world were mighty trees. Look around you, my dear Harry. No
botanist ever before gazed on such a sight!"

My uncle's enthusiasm, always a little more than was required, was now
excusable.

"You are right, Uncle," I remarked. "Providence appears to have designed
the preservation in this vast and mysterious hothouse of antediluvian
plants, to prove the sagacity of learned men in figuring them so
marvelously on paper."

"Well said, my boy--very well said; it is indeed a mighty hothouse. But
you would also be within the bounds of reason and common sense, if you
added that it is also a vast menagerie."

I looked rather anxiously around. If the animals were as exaggerated as
the plants, the matter would certainly be serious.

"A menagerie?"

"Doubtless. Look at the dust we are treading under foot--behold the
bones with which the whole soil of the seashore is covered--"

"Bones," I replied, "yes, certainly, the bones of antediluvian animals."

I stooped down as I spoke, and picked up one or two singular remains,
relics of a bygone age. It was easy to give a name to these gigantic
bones, in some instances as big as trunks of trees.

"Here is, clearly, the lower jawbone of a mastodon," I cried, almost as
warmly and enthusiastically as my uncle; "here are the molars of the
Dinotherium; here is a leg bone which belonged to the Megatherium. You
are right, Uncle, it is indeed a menagerie; for the mighty animals to
which these bones once belonged, have lived and died on the shores of
this subterranean sea, under the shadow of these plants. Look, yonder
are whole skeletons--and yet--"

"And yet, nephew?" said my uncle, noticing that I