them. As I have already said, the operation of nature
is exactly the same as the artificial operation of man.

But if this be true of that simple case, which I put before you, where
there is nothing but the rivalry of one member of a species with others,
what must be the operation of selective conditions, when you recollect
as a matter of fact, that for every species of animal or plant there
are fifty or a hundred species which might all, more or less, be
comprehended in the same climate, food, and station;--that every plant
has multitudinous animals which prey upon it, and which are its direct
opponents; and that these have other animals preying upon them,--that
every plant has its indirect helpers in the birds that scatter abroad
its seed, and the animals that manure it with their dung;--I say, when
these things are considered, it seems impossible that any variation
which may arise in a species in nature should not tend in some way or
other either to be a little better or worse than the previous stock;
if it is a little better it will have an advantage over and tend to
extirpate the latter in this crush and struggle; and if it is a little
worse it will itself be extirpated.

I know nothing that more appropriately expresses this, than the phrase,
"the struggle for existence"; because it brings before your minds, in a
vivid sort of way, some of the simplest possible circumstances connected
with it. When a struggle is intense there must be some who are sure to
be trodden down, crushed, and overpowered by others; and there will be
some who just manage to get through only by the help of the slightest
accident. I recollect reading an account of the famous retreat of
the French troops, under Napoleon, from Moscow. Worn out, tired, and
dejected, they at length came to a great river over which there was
but one bridge for the passage of the vast army. Disorganised and
demoralised as that army was, the struggle must certainly have been a
terrible one--every one heeding only himself, and crushing through the
ranks and treading down his fellows. The writer of the narrative, who
was himself one of those who were fortunate enough to succeed in getting
over, and not among the thousands who were left behind or forced into
the river, ascribed his escape to the fact that he saw striding onward
through the mass a great strong fellow,--one of the French Cuirassiers,
who had on a large blue cloak--and he had enough presence of mind to
ca