and the fronds of some of the ancient ferns are hard to
distinguish from existing ones. At the same time, it must be remembered,
that there is nowhere in the world, at present, any _forest_ which bears
more than a rough analogy with a coal-forest. The types may remain, but
the details of their form, their relative proportions, their associates,
are all altered. And the tree-fern forest of Tasmania, or New Zealand,
gives one only a faint and remote image of the vegetation of the ancient
world.

Once more, an invariably-recurring lesson of geological history, at
whatever point its study is taken up: the lesson of the almost infinite
slowness of the modification of living forms. The lines of the pedigrees
of living things break off almost before they begin to converge.

Finally, yet another curious consideration. Let us suppose that one of
the stupid, salamander-like Labyrinthodonts, which pottered, with much
belly and little leg, like Falstaff in his old age, among the coal-
forests, could have had thinking power enough in his small brain to
reflect upon the showers of spores which kept on falling through years
and centuries, while perhaps not one in ten million fulfilled its
apparent purpose, and reproduced the organism which gave it birth: surely
he might have been excused for moralizing upon the thoughtless and wanton
extravagance which Nature displayed in her operations.

But we have the advantage over our shovel-headed predecessor--or possibly
ancestor--and can perceive that a certain vein of thrift runs through
this apparent prodigality. Nature is never in a hurry, and seems to have
had always before her eyes the adage, "Keep a thing long enough, and you
will find a use for it." She has kept her beds of coal many millions of
years without being able to find much use for them; she has sent them
down beneath the sea, and the sea-beasts could make nothing of them; she
has raised them up into dry land, and laid the black veins bare, and
still, for ages and ages, there was no living thing on the face of the
earth that could see any sort of value in them; and it was only the other
day, so to speak, that she turned a new creature out of her workshop, who
by degrees acquired sufficient wits to make a fire, and then to discover
that the black rock would burn.

I suppose that nineteen hundred years ago, when Julius Caesar was good
enough to deal with Britain as we have dealt with New Zealand, the
primaeval Briton, blue wi