bove the most ancient fossiliferous
beds. Now what do these facts prove? Clearly, they prove that species
which in Wales are separated by strata more than twenty thousand feet
deep, and therefore seem to belong to periods far more remote from each
other, were really co-existent. They prove that the mollusks and
crinoids held to be characteristic of early Silurian strata, and
supposed to have become extinct long before the mollusks and crinoids of
the later Silurian strata came into existence, were really flourishing
at the same time with these last; and that these last possibly date back
to as early a period as the first. They prove that not only the mineral
characters of sedimentary formations, but also the collections of
organic forms they contain, depend, to a great extent, on local
circumstances. They prove that the fossils met with in any series of
strata, cannot be taken as representing anything like the whole Flora
and Fauna of the period they belong to. In brief, they throw great doubt
upon numerous geological generalizations.

Notwithstanding facts like these, and notwithstanding his avowed opinion
that the test of organic remains must be used "under very much the same
restrictions as the test of mineral composition," Sir Charles Lyell,
too, considers sundry positive conclusions to be justified by this test:
even where the community of fossils is slight and the distance great.
Having decided that in various places in Europe, middle Eocene strata
are distinguished by Nummulites; he infers, without any other assigned
evidence, that wherever Nummulites are found--in Morocco, Algeria,
Egypt, in Persia, Scinde, Cutch, Eastern Bengal, and the frontiers of
China--the containing formation is Middle Eocene. And from this
inference he draws the following important corollary:--

"When we have once arrived at the conviction that the nummulitic
formation occupies a middle place in the Eocene series, we are
struck with the comparatively modern date to which some of the
greatest revolutions in the physical geography of Europe, Asia, and
northern Africa must be referred. All the mountain chains, such as
the Alps, Pyrenees, Carpathians, and Himalayas, into the
composition of whose central and loftiest parts the nummulitic
strata enter bodily, could have had no existence till after the
Middle Eocene period."--_Manual_, p. 232.

A still more marked case follows on the next page. Beca