on of the theory advanced by several scientists that the often
bulky trunks of _Syringodendron_ are bases of _Sigillariae_.

[Illustration: 12k: FIG. 11.--_Calamodendron,_ from Autun; prosenchymatous
portion of the wood silicified, X200.]

[Illustration: 12l: FIG. 12.--_Calamodendron,_ from Autun; vascular portion
of the wood silicified.]

If we refer to Fig. 13, which represents a radial vertical section running
through the center of one of the scars that permitted the specimen to be
determined, we shall observe, in fact, a tissue formed of rectangular
cells, longer than wide, arranged in horizontal series, and very analogous
in their aspect to those that we have described in the suberose region of
the bark of Sigillariae. Fig. 15 shows in tangential section the fibrous
aspect of this tissue, which has been rendered denser through compression.
Fig. 14 shows it restored. In Fig. 13, the external part of the bark is
occupied by a thick layer of cellular tissue that exists over the entire
surface of the trunk, but particularly thick near the scars, exactly as in
the barks of the Sigillariae that we have formerly described. Finally, at
_b_, we recognize the undoubted traces of a vascular bundle running to the
leaves. If the bundle appears to be larger than that of the Sigillariae,
this is due to the flattening that the trunk has undergone, the effect of
this having been to spread the bundle out in a vertical plane, although
its greatest width in the first place was in a horizontal one.

[Illustration: 12m: FIG. 13.--_Syringodendron pes-caprae_; from Saarbruck;
radial vertical section, X200.]

[Illustration: 12n: FIG. 14.--Suberose cells restored.]

In anatomical structure, the barks of the Syringodendrons are, then,
analogous to those of the Sigillariae. If, now, we compare the dimensions
of the tissues of these barks with the same silicified tissues of the
barks of Sigillariae, we shall find that there was likewise a diminution in
the dimensions, but yet a less pronounced one than in the woods that we
have previously spoken of. The corky nature of this region of the bark was
likely richer in carbonizable elements than the wood properly so called,
and had, in consequence, to undergo much less shrinkage.--_Dr. B. Renault
(of Paris Museum) in Le Genie Civil_.

[Illustration: 12o: FIG. 15.--_Syringodendron pes-caprae;_ tangential
vertical section in the corky part of the bark, X200.]

DESCRIPTION OF THE FIGURES.--Fig.