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See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1866
1869

→ have no doubt 1872
probably 1859 1860 1861 1866
may have 1869
→ is also 1869 1872
is, however, far more 1859 1860 1861 1866
→ owing to the 1869 1872
there are many unknown 1859 1860 1861 1866
→ OMIT 1869 1872
of growth, which, 1859 1860 1861 1866
→ varies, 1869 1872
of the organisation is modified through variation, 1859 1860
of the organisation is modified through variation 1861 1866
→ other modifications, often 1869 1872
for the good 1859 1860 1861 1866
→ OMIT 1869 1872
being, will cause other modifications, often of the 1859 1860
being, cause other modifications, often of the 1861 1866
→ nature, will ensue. 1869 1872
nature. 1859 1860 1861 1866
→ shape, size, and flavour 1861 1866 1869 1872
seeds 1859 1860
→ seeds of the many 1861 1866 1869 1872
many 1859 1860
→ insect; and these modifications may affect, through correlation, the structure of the adult. 1872
insect. 1859 1860 1861 1866
insect; 1869
↑ 1 blocks not present in 1872; present in 1859 1860 1861 1866 1869
These modifications will no doubt affect, through the laws of correlation, the structure of the adult; and probably in the case of those insects which live only for a few hours, and which never feed, a large part of their structure is merely the correlated result of successive changes in the structure of their larvæ.
→ may 1869 1872
will probably often 1859 1860 1861 1866
→ they 1869 1872
modifications consequent on other modifications at a different period of life, 1859 1860 1861 1866
→ OMIT 1869 1872
in the least degree 1859 1860 1861 1866
→ species would become extinct. 1869 1872
would cause the extinction of the species. 1859 1860 1861 1866
→ whole community; if the community 1872
community; if each in consequence 1859 1860 1861 1866
whole community; if this in consequence 1869
more from a certain disease than yellow
plums;
plums,
whereas another disease attacks yellow-fleshed peaches far more than those with other coloured flesh. If, with all the aids of art, these slight differences make a great difference in cultivating the several varieties, assuredly, in a state of nature, where the trees would have to struggle with other trees and with a host of enemies, such differences would effectually settle which variety, whether a smooth or downy, a yellow or purple fleshed fruit, should succeed.
In looking at many small points of difference between species, which, as far as our ignorance permits us to judge, seem
to be
....
quite unimportant, we must not forget that climate, food, &c., →have no doubt
produce
produced
some
slight and
....
direct effect. It →is also necessary to bear in mind
that
that,
→owing to the
laws
law
of
correlation
correlation,
→OMIT when one part →varies, and the
modifications
variations
are accumulated
by
through
natural
selection
selection,
→other modifications, often of the →OMIT most unexpected →nature, will ensue.
As we see that those variations
which
which,
under domestication appear at any particular period of life, tend to reappear in the offspring at the same period;— for instance, in the →shape, size, and flavour of the →seeds of the many varieties of our culinary and agricultural plants; in the caterpillar and cocoon stages of the
va- rieties
varieties
of the silkworm; in the eggs of poultry, and in the colour of the down of their chickens; in the horns of our sheep and cattle when nearly adult;— so in a state of nature, natural selection will be enabled to act on and modify organic beings at any age, by the accumulation of
profitable variations
variations profitable
at that age, and by their inheritance at a corresponding age. If it profit a plant to have its seeds more and more widely disseminated by the wind, I can see no greater difficulty in this being effected through natural selection, than in the cotton-planter increasing and improving by selection the down in the pods on his
cotton-trees.
cotton trees.
Natural selection may modify and adapt the larva of an insect to a score of contingencies, wholly different from those which concern the mature →insect; and these modifications may affect, through correlation, the structure of the adult. ↑ So, conversely, modifications in the adult →may affect the structure of the larva; but in all cases natural selection will ensure that →they shall not be →OMIT injurious: for if they
became
were
so,
they
the
→species would become extinct.
Natural selection will modify the structure of the young in relation to the parent, and of the parent in relation to the young. In social animals it will adapt the structure of each individual for the benefit of the →whole community; if the community profits by the selected change. What natural selection cannot do, is to modify the structure of one species, without giving it any advantage, for the good of