See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1861
1866
1869
1872

and to 1859 1860 1861 1866
or 1869
and then to 1872

and higher stage may be, in some cases, due merely to 1859 1860 1866
and higher stage may be; in some cases, due merely to 1861
may, in some cases, be the simple result of 1869
may, in many cases, be the simple result of 1872

in two different regions; but I have not much faith in this view; and I attribute the passage of a variety, from a state in which it differs very slightly from its parent to one in which it differs more, 1859 1860 1861 1866
but in most cases they may be attributed 1869

action 1859 1860 1861 1866
gradual accumulative action 1869

in accumulating (as will hereafter 1859 1860 1861 1866
as hereafter to 1869

differences of structure in certain definite directions. 1859 1860 1861 1866
on fluctuating variability. 1869

1 blocks not present in 1859 1860 1861 1866 1869; present in 1872
the nature of the organism and of the different physical conditions to which it has long been exposed; but with respect to the more important and adaptive characters, the passage from one stage of difference to another, may be safely attributed to the cumulative action of natural selection, hereafter to be explained, and to the effects of the increased use or disuse of parts.

Hence I believe a 1859 1860 1861 1866
Hence a 1869
A 1872

views 1859 1860 1861 1866
considerations 1869
considerations to be 1872

whilst in this incipient state 1859 1860 1861 1866
OMIT 1869 1872

Madeira. 1859 1860 1861 1866
Madeira, and with plants by Gaston de Saporta. 1869 1872

strongly-marked
strongly marked
and
more
more
permanent varieties; and at
the
these
latter, as leading to
sub-species
sub-species,
and to species. The
passages
passage
from one stage of difference to another and higher stage may be, in some cases, due merely to the long-continued action of different physical
conditions;
conditions
in two different regions; but I have not much faith in this view; and I attribute the passage of a variety, from a state in which it differs very slightly from its parent to one in which it differs more, to the action of natural
selection,
selection
in accumulating (as will hereafter be more fully
explained,
explained)
differences of structure in certain definite directions. Hence I believe a well-marked variety may
be justly
therefore be
be
called an incipient species; but whether this belief
is
be
justifiable must be judged
of
of
by the
general
general
weight of the
various
several
several
facts and views given throughout this work.
It need not be supposed that all varieties or incipient species
necessarily
necessarily
attain the rank of species. They may whilst in this incipient state become extinct, or they may endure as varieties for very long periods, as has been shown to be the case by Mr. Wollaston with the varieties of certain fossil land-shells in Madeira. If a variety were to flourish so as to exceed in numbers the parent species, it would
them
then
rank as the species, and the species as the variety; or it might come to supplant and exterminate the parent species; or both might co-exist, and both rank as independent species. But we shall hereafter
return
have
to
return to
return to
this subject.
From these remarks it will be seen that I look at the term
species
species,
as one arbitrarily
given,
given
for the sake of
convenience,
convenience
to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms. The term variety, again, in comparison with mere individual differences, is also applied arbitrarily,
and
and
for
mere
mere
convenience
convenience'
sake.