ird chapter.

It is quite conceivable that the material organic world may be so
constituted that the simultaneous action upon it of all known forces,
mechanical, physical, chemical, magnetic, terrestrial, and cosmical,
together with other as yet unknown forces which probably exist, may result
in changes which are harmonious and symmetrical, just as the internal
nature of vibrating plates causes particles of sand scattered over them to
assume definite and symmetrical figures when made to oscillate in different
ways by the bow of a violin being drawn along their edges. The results of
these combined internal powers and external influences might be represented
under the symbol of complex series of vibrations (analogous to those of
sound or light) forming a most complex harmony or a display of most varied
colours. In such a way the reparation of local injuries might be symbolized
as a filling up and completion of an interrupted rhythm. Thus also
monstrous aberrations from typical structure might correspond to a discord,
and sterility from crossing be compared with the darkness resulting from
the interference of waves of light.

Such symbolism will harmonize with the peculiar reproduction, before
mentioned, of heads in the body of certain annelids, with the facts of
serial homology, as well as those of bilateral and vertical symmetry. {230}
Also, as the atoms of a resonant body may be made to give out sound by the
juxtaposition of a vibrating tuning-fork, so it is conceivable that the
physiological units of a living organism may be so influenced by
surrounding conditions (organic and other) that the accumulation of these
conditions may upset the previous rhythm of such units, producing
modifications in them--a fresh chord in the harmony of nature--a new
species!

But it may be again objected that to say that species arise by the help of
an innate power possessed by organisms is no explanation, but is a
reproduction of the absurdity, _l'opium endormit parcequ'il a une vertu
soporifique_. It is contended, however, that this objection does not apply,
even if it be conceded that there is that force in Moliere's ridicule which
is generally attributed to it.[231] Much, however, might be said in
opposition to more than one of that brilliant dramatist's smart
philosophical epigrams, just as to the theological ones of Voltaire, or to
the biological one of that other Frenchman who for a time discredited a
cranial skeletal theory by t