of, those of De Maillet; and though Linnaeus may have played with the
hypothesis of transmutation, it obtained no serious support until
Lamarck adopted it, and advocated it with great ability in his
'Philosophie Zoologique.'

Impelled towards the hypothesis of the transmutation of species, partly
by his general cosmological and geological views; partly by the
conception of a graduated, though irregularly branching, scale of
being, which had arisen out of his profound study of plants and of the
lower forms of animal life, Lamarck, whose general line of thought often
closely resembles that of De Maillet, made a great advance upon the
crude and merely speculative manner in which that writer deals with the
question of the origin of living beings, by endeavouring to find
physical causes competent to effect that change of one species into
another, which De Maillet had only supposed to occur. And Lamarck
conceived that he had found in Nature such causes, amply sufficient for
the purpose in view. It is a physiological fact, he says, that organs
are increased in size by action, atrophied by inaction; it is another
physiological fact that modifications produced are transmissible to
offspring. Change the actions of an animal, therefore, and you will
change its structure, by increasing the development of the parts newly
brought into use and by the diminution of those less used; but by
altering the circumstances which surround it you will alter its
actions, and hence, in the long run, change of circumstance must
produce change of organization. All the species of animals, therefore,
are, in Lamarck's view, the result of the indirect action of changes of
circumstance, upon those primitive germs which he considered to have
originally arisen, by spontaneous generation, within the waters of the
globe. It is curious, however, that Lamarck should insist so strongly*
as he has done, that circumstances never in any degree directly modify