, "the father of historical geology," in the closing decade
of the eighteenth century. Smith was the first to make a systematic use
of fossils in determining the order of succession of the rocks which
make up the accessible crust of the earth, and this use has continued,
without essential change, to the present day. It is true that the
theory of evolution has greatly modified our conceptions concerning the
introduction of new species and the manner in which palaeontological
data are to be interpreted in terms of stratigraphy, but, broadly
speaking, the method remains fundamentally the same as that introduced
by Smith.

The biological direction of palaeontology was due to Cuvier and his
associates, who first showed that fossils were not merely varieties
of existing organisms, but belonged to extinct species and genera,
an altogether revolutionary conception, which startled the scientific
world. Cuvier made careful studies, especially of fossil vertebrates,
from the standpoint of zoology and was thus the founder of palaeontology
as a biological science. His great work on "Ossements Fossiles" (Paris,
1821) has never been surpassed as a masterpiece of the comparative
method of anatomical investigation, and has furnished to the
palaeontologist the indispensable implements of research.

On the other hand, Cuvier's theoretical views regarding the history
of the earth and its successive faunas and floras are such as no one
believes to-day. He held that the earth had been repeatedly devastated
by great cataclysms, which destroyed every living thing, necessitating
an entirely new creation, thus regarding the geological periods as
sharply demarcated and strictly contemporaneous for the whole earth,
and each species of animal and plant as confined to a single period.
Cuvier's immense authority and his commanding personality dominated
scientific thought for more than a generation and marked out the line
which the development of palaeontology was to follow. The work was
enthusiastically taken up by many very able men in the various European
countries and in the United States, but, controlled as it was by the
belief in the fixity of species, it remained almost entirely descriptive
and consisted in the description and classification of the different
groups of fossil organisms. As already intimated, this narrowness of
view had its compensations, for it deferred generalisations until some
adequate foundations for these had been laid.