150 LAMARCK, HIS LIFE AND WORK 
and sudden extinctions of life, and as sudden recrea- 
tions. Cuvier was a natural leader of men, a ready 
debater, and a clear, forcible writer, a man of great 
executive force, but lacking in insight and imagina- 
tion ; he dominated scientific Paris and France, he was 
the law-giver and autocrat of the laboratories of Paris, 
and the views of quiet, thoughtful, profound scholars 
such as Lamarck and Geoffroy St. Hilaire were dis- 
dainfully pushed aside, overborne, and the progress 
of geological thought was arrested, while, owing to 
his great prestige, the rising views of the Lamarckian 
school were nipped in the bud. Every one, after the 
appearance of Cuvier’s great work on fossil mammals 
and of his Régne Animal, was a Cuvierian, and down 
to the time of Lyell and of Charles Darwin all natural- 
ists, with only here and there an exception, were pro- 
nounced Cuvierians in biology and geology—catas- 
trophists rather than uniformitarians. We now, with 
the increase of knowledge of physical and historical 
geology, of the succession of life on the earth, of the 
unity of organization pervading that life from monad 
to man all through the ages from the Precambrian to 
the present age, know that there were vast periods 
of preparation followed by crises, perhaps geologically 
brief, when there were widespread changes in physi- 
cal geography, which reacted on the life-forms, render- 
ing certain ones extinct, and modifying others; but 
this conception is entirely distinct from the views of 
Cuvier and his school, * which may, in the light of 
* Cuvier, in speaking of these revolutions, ‘‘ which have changed 
the surface of our earth,” correctly reasons that they must have ex- 
cited a more powerful action upon terrestrial quadrupeds than upon 
