TION

In an earlier chapter it was stated that the story of life is a story
of gradual and continuous advance, with occasional periods of more rapid
progress. Hitherto it has been, in these pages, a slow and even advance
from one geological age to another, one level of organisation to
another. This, it is true, must not be taken too literally. Many
a period of rapid change is probably contained, and blurred out of
recognition, in that long chronicle of geological events. When a region
sinks slowly below the waves, no matter how insensible the subsidence
may be, there will often come a time of sudden and vast inundations, as
the higher ridges of the coast just dip below the water-level and the
lower interior is flooded. When two invading arms of the sea meet at
last in the interior of the sinking continent, or when a land-barrier
that has for millions of years separated two seas and their populations
is obliterated, we have a similar occurrence of sudden and far-reaching
change. The whole story of the earth is punctuated with small
cataclysms. But we now come to a change so penetrating, so widespread,
and so calamitous that, in spite of its slowness, we may venture to call
it a revolution.

Indeed, we may say of the remaining story of the earth that it is
characterised by three such revolutions, separated by millions of years,
which are very largely responsible for the appearance of higher types of
life. The facts are very well illustrated by an analogy drawn from the
recent and familiar history of Europe.

The socio-political conditions of Europe in the eighteenth century,
which were still tainted with feudalism, were changed into the
socio-political conditions of the modern world, partly by a slow and
continuous evolution, but much more by three revolutionary movements.
First there was the great upheaval at the end of the eighteenth century,
the tremors of which were felt in the life of every country in Europe.
Then, although, as Freeman says, no part of Europe ever returned
entirely to its former condition, there was a profound and almost
universal reaction. In the 'thirties and 'forties, differing in
different countries, a second revolutionary disturbance shook Europe.
The reaction after this upheaval was far less severe, and the conditions
were permanently changed to a great extent, but a third revolutionary
movement followed in the next generation, and from that time the
evolution of socio-political conditions h