according as they near the tropics. That the ferns and club mosses
have diminished with the decrease of temperature of the earth, is
proved by comparing the fossil club mosses, which have been found as
large as beech trees, whereas at the present time the most gigantic
club moss rarely exceeds three feet in height. In the lower sections
of the third, fourth, and fifth cases, the visitor may notice some
fine specimens of polished fossil woods; but the varieties of
vegetable fossils can hardly engage his serious attention for any
length of time, unless he have some real knowledge of botany and
geology; yet he may gather the solemn teaching that lies in those dark
masses of early coal formation and clay slate, even though he be
unable to explain the first principles of botanical science. He may
notice, however, in the fifth and sixth wall cases, fossil specimens
of extinct plants, including the sigillaria, which, when living, is
supposed to have attained often to the height of seventy feet. Having
noticed these vegetable remains, the visitor should cross to the
northern wall of the room, and examine the sandstones upon which the
tracks of an extinct animal called the chirotherium--and footprints,
supposed to be of birds, are distinguishable.

The central object in the room is a tortoise found in Hindostan, near
Allahabad. It is carved out of nephrite or jade, and is deposited upon
a curious table of inlaid ancient marbles. Against the eastern wall
are deposited some beautiful varieties of branched native silver from
Norway; Lady Chantrey's specimen of part of a coniferous tree,
semi-opalised; and a mass of websterite from Newhaven, Sussex. The
table cases now remain for examination. These are devoted to varieties
of

MINERALS.