ns, and doubtless would have continued to make it
the object of his private thought, had he not found Leibnitz upon his
track. Darwin for two-and-twenty years pondered the problem of the
origin of species, and doubtless he would have continued to do so had
he not found Wallace upon his track. [Footnote: The behaviour of Mr.
Wallace in relation to this subject has been dignified in the highest
degree.] A concentrated, but full and powerful, epitome of his
labours was the consequence. The book was by no means an easy one;
and probably not one in every score of those who then attacked it, had
read its pages through, or were competent to grasp their significance
if they had. I do not say this merely to discredit them: for there
were in those days some really eminent scientific men, entirely raised
above the heat of popular prejudice, and willing to accept any
conclusion that science had to offer, provided it was duly backed by
fact and argument, who entirely mistook Mr. Darwin's views. In fact,
the work needed an expounder, and it found one in Mr. Huxley. I know
nothing more admirable in the way of scientific exposition than those
early articles of his on the origin of species. He swept the curve of
discussion through the really significant points of the subject,
enriched his exposition with profound original remarks and
reflections, often summing up in a single pithy sentence an argument
which a less compact mind would have spread over pages. But there is
one impression made by the book itself which no exposition of it,
however luminous, can convey; and that is the impression of the vast
amount of labour, both of observation and of thought, implied in its
production. Let us glance at its principles.

It is conceded on all hands that what are called varieties' are
continually produced. The rule is probably without exception. No
chick, or child, is in all respects and particulars the counterpart of
its brother and sister; and in such differences we have 'variety'
incipient. No naturalist could tell how far this variation could be
carried; but the great mass of them held that never, by any amount of
internal or external change, nor by the mixture of both, could the
offspring of the same progenitor so far deviate from each other as to
constitute different species. The function of the experimental
philosopher is to combine the conditions of Nature and to produce her
results; and this was the method of Darwin. [Foot