Figs. 1 and 2 (magnified two hundred times) represent two sections, made in rectangular planes, of fragments of Lancashire cannel coal.  In a certain measure, they remind one of Figs. 4 and 5, Pl 11, of Witham’s “Internal Structure of Fossil Vegetables,” and which were drawn from specimens of cannel coal derived likewise from Lancashire, but which are not so highly magnified.  There is an interesting fact to note in this coincidence, and that is that this structure, which is so difficult to explain in its details, is not accidental, but a consequence of the nature 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.