by the presence of certain "reticulations" which distinguish that
family, in addition to the usual radiating and concentric lines.
That particular tree was concluded to be an araucaria, a species now
found in Norfolk Island, in the South Sea, and in a few other remote
situations. The coniferae of this era form the dawn of
dicotyledenous trees, of which they may be said to be the simplest
type, and to which, it has already been noticed, the lepidodendra are
a link from the monocotyledons. The concentric rings of the
Craigleith and other coniferae of this era have been mentioned. It
is interesting to find in these a record of the changing seasons of
those early ages, when as yet there were no human beings to observe
time or tide. They are clearly traced; but it is observed that they
are more slightly marked than is the case with their family at the
present day, as if the changes of temperature had been within a
narrower range.

Such was the vegetation of the carbonigenous era, composed of forms
at the bottom of the botanical scale, flowerless, fruitless, but
luxuriant and abundant beyond what the most favoured spots on earth
can now shew. The rigidity of the leaves of its plants, and the
absence of fleshy fruits and farinaceous seeds, unfitted it to afford
nutriment to animals; and, monotonous in its forms, and destitute of
brilliant colouring, its sward probably unenlivened by any of the
smaller flowering herbs, its shades uncheered by the hum of insects,
or the music of birds, it must have been but a sombre scene to a
human visitant. But neither man nor any other animals were then in
existence to look for such uses or such beauties in this vegetation.
It was serving other and equally important ends, clearing (probably)
the atmosphere of matter noxious to animal life, and storing up
mineral masses which were in long subsequent ages to prove of the