state of
perpetual carnage and strife, individual against individual, fighting
for sustenance and life.

That idea fully imagined, it becomes plain that a selective influence
is all the time at work in nature, since only a few individuals,
relatively, of each generation can come to maturity, and these few
must, naturally, be those best fitted to battle with the particular
circumstances in the midst of which they are placed. In other words, the
individuals best adapted to their surroundings will, on the average, be
those that grow to maturity and produce offspring. To these
offspring will be transmitted the favorable peculiarities. Thus these
peculiarities will become permanent, and nature will have accomplished
precisely what the human breeder is seen to accomplish. Grant that
organisms in a state of nature vary, however slightly, one from another
(which is indubitable), and that such variations will be transmitted by
a parent to its offspring (which no one then doubted); grant, further,
that there is incessant strife among the various organisms, so that
only a small proportion can come to maturity--grant these things, said
Darwin, and we have an explanation of the preservation of variations
which leads on to the transmutation of species themselves.

This wonderful coign of vantage Darwin had reached by 1839. Here was the
full outline of his theory; here were the ideas which afterwards came to
be embalmed in familiar speech in the phrases "spontaneous variation,"
and the "survival of the fittest," through "natural selection." After
such a discovery any ordinary man would at once have run through the
streets of science, so to speak, screaming "Eureka!" Not so Darwin. He
placed the manuscript outline of his theory in his portfolio, and went
on gathering facts bearing on his discovery. In 1844 he made an abstract
in a manuscript book of the mass of facts by that time accumulated.
He showed it to his friend Hooker, made careful provision for its
publication in the event of his sudden death, then stored it away in
his desk and went ahead with the gathering of more data. This was the
unexploded powder-mine to which I have just referred.

Twelve years more elapsed--years during which the silent worker gathered
a prodigious mass of facts, answered a multitude of objections that
arose in his own mind, vastly fortified his theory. All this time
the toiler was an invalid, never knowing a day free from illness and
discomfort, o