surface, set volcanoes belching out fire and fumes in many parts,
stripped it of its great forests, and slew the overwhelming majority
of its animals. On the scale of geological time it may be called a
revolution.

It must be confessed that the series of disturbances which close the
Secondary and inaugurate the Tertiary Era cannot so conveniently be
summed up in a single formula. They begin long before the end of the
Mesozoic, and they continue far into the Tertiary, with intervals of
ease and tranquillity. There seems to have been no culminating point in
the series when the uplifted earth shivered in a mantle of ice and
snow. Yet I propose to retain for this period--beginning early in the
Cretaceous (Chalk) period and extending into the Tertiary--the name of
the Cretaceous Revolution. I drew a fanciful parallel between the three
revolutions which have quickened the earth since the sluggish days of
the Coal-forest and the three revolutionary movements which have changed
the life of modern Europe. It will be remembered that, whereas the first
of these European revolutions was a sharp and massive upheaval,
the second consisted in a more scattered and irregular series of
disturbances, spread over the fourth and fifth decades of the nineteenth
century; but they amounted, in effect, to a revolution.

So it is with the Cretaceous Revolution. In effect it corresponds very
closely to the Permian Revolution. On the physical side it includes a
very considerable rise of the land over the greater part of the globe,
and the formation of lofty chains of mountains; on the botanical side
it means the reduction of the rich Mesozoic flora to a relatively
insignificant population, and the appearance and triumphant spread of
the flowering plants, on the zoological side it witnesses the complete
extinction of the Ammonites, Deinosaurs, and Pterosaurs, an immense
reduction of the reptile world generally, and a victorious expansion of
the higher insects, birds, and mammals; on the climatic side it provides
the first definite evidence of cold zones of the earth and cold seasons
of the year, and seems to represent a long, if irregular, period of
comparative cold. Except, to some extent, the last of these points,
there is no difference of opinion, and therefore, from the evolutionary
point of view, the Cretaceous period merits the title of a revolution.
All these things were done before the Tertiary period opened.

Let us first consider the f