at the present day;" and he appeals
to a class of facts, confessedly obscure, which have not been, as he
thinks, satisfactorily accounted for by the law which usually regulates
the production of organic beings. He refers us to the speculations of
Dr. Allen Thomson on the primitive production of Infusoria,[46] to the
facts which modern science, aided by the microscope, has discovered
respecting the Entozoa, or the creatures which live within the bodies of
others, and, above all, to the experiments of Mr. Crosse and Mr. Weekes,
which seemed to result in the production of a small species of insect
(_Acarus Crossii_) from the action of a voltaic battery on a saturated
solution of the silicate of potash, or the nitrate of copper, or the
ferrocyanate of potassium. The reason of his anxiety to avail himself of
these cases is evident. The exigencies of his theory demanded a method
of accounting for the primary origin of life different from any that can
be found in the common process of propagation. He saw clearly enough
that his main argument, founded, as it was, on the law of hereditary
transmission, could not account for the production of the first
organism; and that, if he would avoid either the doctrine of _Immediate
Creation_, which is so offensive to him, or the idea of _Eternal
Generation_, which is utterly excluded by the clearest lessons of Fossil
Geology, he must have recourse to the hypothesis of _Spontaneous
Generation_. Hence he attempts to account for the commencement of new
species both of plants and animals, in the course of the world's
history, by a transmutation of species; while, for the origin of the
first species, he has recourse to the same law of Development, but
acting in widely different circumstances, and giving rise to what he
calls "aboriginal generation," whereby the inorganic passes into the
organic, and life, form, and structure, are imparted to hitherto inert
materials by the action of Electricity on mucus or albumen. To
accomplish this twofold purpose, he felt it necessary to insist, in the
first instance, on the ordinary law of generation as the established
order of _mediate_ creation; while he found it equally necessary, in the
second place, to insist on those apparently exceptional cases in which
the connection between the germ and the product has hitherto eluded
philosophical research,--and this for the purpose of showing that the
original production of plants and animals was _not similar_ to