thicker part of the stem is in
such a state of keeping, that it presents to the microscope, in a sliced
preparation, the internal structure, and exhibits, as in recent
coniferous twigs of a year's growth, a central pith, a single ring of
reticulated tissue arranged in lines that radiate outwards, and a thin
layer of enveloping bark. Nothing, then, can be more certain than that
this ancient twig, which must be accepted as representative of the
foliage of whole forests of the Secondary ages in Scotland, formed part
of a conifer of the Lias; and the foliage of several of the other twigs,
its contemporaries, though I have failed to demonstrate their true
character in the same way, bear a scarce less coniferous aspect. The
cones of the period, from the circumstance that they are locked up in a
hard limestone that clings closely around their scales, and from the
further circumstance that the semi-calcareous lignite into which they
are resolved is softer and less tenacious than the enclosing matrix,
present, when laid open, not their outer surfaces, but mere sections of
their interior; and give, in consequence, save in their general
proportions and outline, but few specific marks by which to distinguish
them. We see, however, in some cases in these sections what would be
otherwise unseen,--the flat naked seeds lying embedded in their hollow
receptacles between the scales, and in as perfect a state of keeping as
the seeds of recent pines that had ripened only a twelvemonth ago. Had
not the vitality of seeds its limits in time, like life of all other
kinds, one might commit these perfect fossil germs to the soil, in the
hope of seeing the old extinct forests called, through their agency, a
second time into existence. Of three apparent species of cones which
occur in the Eathie Lias, the smallest seems to have resembled in size
and appearance that of the Scotch fir; the largest, which consisted from
bottom to top, as seen in section, of from nine to ten scales, appears
to have been more in the proportions of the oblong oval cones of the
spruce family; while a cone of intermediate length, but of considerably
greater breadth, assumed the rounded form of the cones of the cedar. I
have found in the same deposit what seems to be the sprig of a conifer,
with four apparently embryo cones attached to it in the alternate order.
These are rather more sessile than the young cones of the larch; but the
aspect of the whole is that of a larch tw