variation under domestication, afforded the best and safest clue. I
may venture to express my conviction of the high value of such
studies, although they have been very commonly neglected by
naturalists.

From these considerations, I shall devote the first chapter of this
Abstract to Variation under Domestication. We shall thus see that a
large amount of hereditary modification is at least possible, and,
what is equally or more important, we shall see how great is the power
of man in accumulating by his Selection successive slight variations.
I will then pass on to the variability of species in a state of
nature; but I shall, unfortunately, be compelled to treat this subject
far too briefly, as it can be treated properly only by giving long
catalogues of facts. We shall, however, be enabled to discuss what
circumstances are most favourable to variation. In the next chapter
the Struggle for Existence amongst all organic beings throughout the
world, which inevitably follows from their high geometrical powers of
increase, will be treated of. This is the doctrine of Malthus, applied
to the whole animal and vegetable kingdoms. As many more individuals
of each species are born than can possibly survive; and as,
consequently, there is a frequently recurring struggle for existence,
it follows that any being, if it vary however slightly in any manner
profitable to itself, under the complex and sometimes varying
conditions of life, will have a better chance of surviving, and thus
be NATURALLY SELECTED. From the strong principle of inheritance, any
selected variety will tend to propagate its new and modified form.

This fundamental subject of Natural Selection will be treated at some
length in the fourth chapter; and we shall then see how Natural
Selection almost inevitably causes much Extinction of the less