shale, limestone, and ironstone, in which we seem to see the ashes of
primitive organisms, cremated in the appalling fires of the volcanic
age, or crushed out of recognition by the superimposed masses. Even if
some wizardry of science were ever to restore the forms that have been
reduced to ashes in this Archaean crematorium, it would be found that
they are more or less advanced forms, far above the original level of
life. No trace will ever be found in the rocks of the first few million
years in the calendar of life.

The word impossible or unknowable is not lightly uttered in science
to-day, but there is a very plain reason for admitting it here. The
earliest living things were at least as primitive of nature as the
lowest animals and plants we know to-day, and these, up to a fair level
of organisation, are so soft of texture that, when they die, they leave
no remains which may one day be turned into fossils. Some of them,
indeed, form tiny shells of flint or lime, or, like the corals, make for
themselves a solid bed; but this is a relatively late and higher stage
of development. Many thousands of species of animals and plants lie
below that level. We are therefore forced to conclude, from the aspect
of living nature to-day, that for ages the early organisms had no hard
and preservable parts. In thus declaring the impotence of geology,
however, we are at the same time introducing another science, biology,
which can throw appreciable light on the evolution of life. Let us first
see what geology tells us about the infancy of the earth.

The distribution of the early rocks suggests that there was
comparatively little dry land showing above the surface of the Archaean
ocean. Our knowledge of these rocks is not at all complete, and we must
remember that some of this primitive land may be now under the sea or
buried in unsuspected regions. It is significant, however, that, up to
the present, exploration seems to show that in those remote ages only
about one-fifth of our actual land-surface stood above the level of the
waters. Apart from a patch of some 20,000 square miles of what is now
Australia, and smaller patches in Tasmania, New Zealand, and India,
nearly the whole of this land was in the far North. A considerable area
of eastern Canada had emerged, with lesser islands standing out to the
west and south of North America. Another large area lay round the basin
of the Baltic; and as Greenland, the Hebrides, and the extr