pecies. He
pronounced it probable that all changes in the organic, as well as in
the inorganic world, were the result of law, and not of miraculous
interposition. He seems to have been led to his opinion that the change
of species had been gradual by the difficulty experienced in
distinguishing species from varieties by the almost perfect gradation of
forms in certain groups, and by the analogy of domestic productions.
With respect to the means of modification, he attributed something to
the direct action of the physical conditions of life, something to the
crossing of already existing forms, and much to use and disuse, or, in
other words, to the effect of habit. Finally, he held that characters
acquired by an existing individual might be transmitted to its
offspring.

In 1813 Dr. W.C. Wells read before the Royal Society "An Account of a
White Female, Part of whose Skin resembles that of a Negro." In this
paper the author distinctly recognized the principle of natural
selection, but applied it only to the races of man, and in man only to
certain characters. After remarking that negroes and mulattoes enjoy an
immunity from certain tropical diseases, he observed, first, that all
animals tend to vary in some degree, and, secondly, that
agriculturalists improve their domesticated animals by selection. He
added that what is done in the latter case by art seems to be done with
equal efficacy, though more slowly, by nature in the formation of
varieties of mankind fitted for the countries which they inhabit. Again
in 1831 Mr. Patrick Matthew published a work on "Naval Timber and
Arboriculture," in which he put forth precisely the same view
concerning the origin of species as that propounded by Mr. Wallace and
by Darwin. Unfortunately for himself, the view was cursorily suggested
in scattered passages of an appendix to a work on a different subject,
so that it remained unnoticed until Mr. Matthew himself drew attention
to it in 1860, after the publication of the "Origin of Species." We
observe finally that Mr. Herbert Spencer, in an essay published in 1852,
and republished six years later, contrasted the theories of the creation
and the development of organic beings. He argued from the analogy of
domestic productions, from the changes which the embryos of many species
undergo, from the difficulty of distinguishing species and varieties,
and from the principle of general gradation, that species have been
modified; and he attribu