may term the "saccular matter" of the coal, which, either in its
primary or in its degraded form constitutes by far the greater part of
all the bituminous coals I have examined, is certainly not mineral
charcoal; nor is its structure that of any stem or leaf. Hence its real
nature is at first by no means apparent, and has been the subject of much
discussion.

The first person who threw any light upon the problem, as far as I have
been able to discover, was the well-known geologist, Professor Morris. It
is now thirty-four years since he carefully described and figured the
coin-shaped bodies, or larger sacs, as I have called them, in a note
appended to the famous paper "On the Coalbrookdale Coal-Field," published
at that time, by the present President of the Geological Society, Mr.
Prestwich. With much sagacity, Professor Morris divined the real nature
of these bodies, and boldly affirmed them to be the spore-cases of a
plant allied to the living club-mosses.

But discovery sometimes makes a long halt; and it is only a few years
since Mr. Carruthers determined the plant (or rather one of the plants)
which produces these spore-cases, by finding the discoidal sacs still
adherent to the leaves of the fossilized cone which produced them. He
gave the name of _Flemingites gracilis_ to the plant of which the cones
form a part. The branches and stem of this plant are not yet certainly
known, but there is no sort of doubt that it was closely allied to the
_Lepidodendron_, the remains of which abound in the coal formation. The
_Lepidodendra_ were shrubs and trees which put one more in mind of an
_Araucaria_ than of any other familiar plant; and the ends of the
fruiting branches were terminated by cones, or catkins, somewhat like the
bodies so named in a fir, or a willow. These conical fruits, however, did
not produce seeds; but the leaves of which they were composed bore upon
their surfaces sacs full of spores or sporangia, such as those one sees
on the under surface of a bracken leaf. Now, it is these sporangia of the
Lepidodendroid plant _Flemingites_ which were identified by Mr.
Carruthers with the free sporangia described by Professor Morris, which
are the same as the large sacs of which I have spoken. And, more than
this, there is no doubt that the small sacs are the spores, which were
originally contained in the sporangia.

The living club-mosses are, for the most part, insignificant and creeping
herbs, which, superficially