e works Lamarck upholds fully the descent and
evolution theory, and maintains that the simplest organisms are generated
through a _generatio spontanea_, which is still taking place; but that all
the more developed organisms, including man, are descended through a
gradual change from other species. With this theory, he put himself in
direct and conscious opposition to the old doctrine of the immutability of
species and their characteristics, which had been ably maintained by
Linnaeus, and also made some attempts at explanation which approach very
nearly the selection theory. A change in the physical conditions of life,
especially the force of habit in the use or disuse of the organs, the
inheritance of physical and psychical {31} qualities thus attained, and the
extension of the process of transmutation into extraordinarily long periods
of time with very slight changes, are also, in his view, the probable
causes of the variation and development of the species. He only lacks the
idea of a natural selection in the struggle for existence, and the
comparison of the processes in nature with the methodical selection of man
in the breeding of domestic animals and plants, to identify his views with
those of Darwin.

At first, Lamarck met only with violent opposition; but after a little
while his views ceased to attract attention. The time had not yet come to
make such an attempt at observing nature from the standpoint of evolution.
The sciences which favor such a mode of observation, and even demand
it--such as comparative anatomy and physiology and the history of the
development of the different plants and animals--were only in their
infancy, or were--like palaeontology and the comparative geography of plants
and animals--not yet in existence. The influence of Linnaeus, whose views
diametrically opposed those of Lamarck, predominated over all the
investigations of natural science; Buffon, who favored the ideas of
Lamarck, and loved to trace a unity in natural phenomena, was too instable
in his investigations and views to arrive at a comprehensive principle; and
even the eminent naturalist, Cuvier, of Montpellier, showed in his
observation of nature a predilection for analysis rather than synthesis,
and although his comprehensive mind inclined to generalize and explain, he
placed himself in decided opposition to a theory which was founded only on
a few decisive facts.

This last mentioned deficiency seems to have been {32} the m