eld in
reserve in birds for this fate) which is destined to form in the centre
the principal keel of this new machine" (p. 84). Again, with reference
to the homology of the ossicles of the ear with the opercular bones in
fish, "employing other resources equally hidden and rudimentary, Nature
makes profitable use of the four tiny ossicles lodged in the auditory
passage, and, raising them in fish to the greatest possible dimensions,
forms from them these broad opercula...." (p. 85). Or you may take it
the other way about, and start from the organisation of fishes;
opercular bones are of no use to air-breathing animals, so they dwindle
away, and are pressed into the service of the ear, although they are of
little use in hearing (p. 46).

There is here no thought of evolution; in later years, however, his
researches upon fossil crocodilians led him to consider the possibility
that the living species were descended from the antediluvian. For the
factors of the transformation he refers to Lamarck's hypotheses.[98] In a
memoir of 1828,[99] dealing with the possible genetic relation of living
to fossil species, he still regards the question as more or less open.
Although fossil species are mostly different from living species are we
therefore to conclude, he asks, that they are not the ancestors of the
present day forms? "The contrary idea arises more naturally in the mind;
for otherwise the six-days' creation would have had to be repeated and
new beings produced by a fresh creation. Now this proposition, contrary
as it is to the most ancient historical traditions, is inadmissible" (p.
210). It is sufficiently clear from this quotation that Geoffroy was
thinking only of a transformation of the antediluvian species created by
God, and by no means of an evolution of all species from one primitive
type. In matters of religion Geoffroy was orthodox. He goes on to point
out how great a resemblance there is in essential structure between
fossil and living species. All find their place in one scheme of
classification; does it not seem that all are modifications "of one
single being, of that abstract being or common type, which it is always
possible to denote by the same name?" (p. 211). This type is abstract,
not actual, and it is certainly not conceived as an original ancestor of
all animals.

The fullest development of Geoffroy's views on evolution is found in his
memoir "Le degre d'influence du monde ambiant pour modifier les form