acquainted. But the state of
keeping of the specimen is not good, nor do I know that another has yet
been found. Further, in the same beds Dr. Fleming found a curious
nondescript vegetable, or rather part of a vegetable, with smooth narrow
stems, resembling those of the smooth-stemmed organism of the Caithness
flagstones, but unlike it in the circumstance that its detached nearly
parallel stalks anastomose with each other by means of cross branches,
that unite them in the middle, somewhat in the style of the Siamese
twins. I have heard the doctor suggest, but know not whether he has
placed the remark on record, that these parallel stems may have been but
the internal fibres of some larger plant, whose more succulent portions
have disappeared; and certainly, while such instances of anastomosis are
rare among the _stems_ of plants, they are common enough among their
_internal fibres_, as all who have examined the macerated _debris_ of a
kitchen-garden or a turnip-field must have had occasion to remark. We
sometimes, however, find cases of anastomosis among the stems of even
the higher plants. I have seen oftener than once, in neglected hawthorn
hedges, the branch of one plant entering into the stem of another, and
becoming incorporated with its substance; and we are told by Professor
Balfour, that this kind of chance adhesion is often seen in the branches
of the ivy; and that not unfrequently, by a similar process, the roots
of contiguous trees are united. Nor does it seem improbable, that what
occasionally takes place among the higher plants of the present time may
have been common among some of the comparatively low plants of so
ancient a period as that of the Middle Old Red Sandstone. This formation
of the gray tilestones has furnished one vegetable organism apparently
higher in the scale than those just described, in a well marked
Lepidodendron, which exhibits, like the Araucarian of the Lower Old Red,
though less distinctly, the internal structure. It was found about
sixteen years ago in a pavement quarry near Clockbriggs,--the last
station on the Aberdeen and Forfar Railway as the traveller approaches
the town of Forfar from the north. I owe my specimen of this ancient
Lepidodendron to Mr. William Miller, banker, Dundee, an accomplished
geologist, who has taken no little trouble in determining its true
history. He has ascertained that it occurred deep in the rock,
seventy-one feet from the surface; that the beds whic