ure of the materials that served to produce the coal of this region.
In the midst of a mass of blackish debris, _a_, organic and inorganic,
and immersed in an amorphous and transparent gangue, we find a few
recognizable fragments, such as thick-walled macrospores, _b_, of
various sizes, bits of flattened petioles, _c_, pollen grains, _d_,
debris of bark, etc. In Fig. 2 all these different remains are cut
either obliquely or longitudinally, and are not very recognizable. It is
not rare to meet with a sort of vacuity, _e_, filled with clearer matter
of resinoid aspect, without organization.

[Illustration: 12c: FIG. 3.--Commentry cannel coal, X200.]

In Fig. 3, which represents a section made from Commentry cannel coal,
the number of recognizable organs in the midst of the mass of debris is
much larger. Thus, at _a_ we see a macrospore, at _b_ a fragment of the
coat of a macrospore, at _c_ another macrospore having a silicified
nucleus, such as has been found in no other case, at _d_ we have a
transverse section of a vascular bundle, at _e_ a longitudinal section
of a rootlet traversed by another one, at _f_ we have a transverse
section of another rootlet, at _g_ an almost entire portion of the
vascular bundle of a root, and at _h_ we see large pollen grains
recalling those that we meet with in the silicified seeds from Saint
Etienne.

Cannel coal, then, shows that it is formed of a sort of dark brown gangue
of resinoid aspect (when a thin section of it is examined) holding in
suspension indeterminable black organic and inorganic debris, which are
arranged in layers, and in the midst of which (according to the locality
and the fragment studied) is found a varying number of easily recognized
vegetable organs.

[Illustration: 12d: FIG. 4.--Pennsylvania anthracite, X200.]

It is very rare that anthracite offers any discernible trace of
organization. Preparations made from fragments of Sable and Lamore coal
could not be made sufficiently thin to be transparent; the mass remained
very opaque, and the clearest parts exhibited merely amorphous,
irregular granulations. Still, fragments of anthracite from Pennsylvania
furnished, amid a dominant mass of dark, yellow-brown, structureless
substance, a few organized vegetable debris, such as a fragment of a
vascular bundle with radiating elements (Fig. 4, _a_), a macrospore,
_b_, and a few pollen grains or microspores, _c_.

[Illustration: 12e: FIG. 5.--Boghead from New South Wa