See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1869
1872

as much difficulty, 1859 1860 1861 1866
great difficulty in understanding the origin or formation of parts of little importance; almost as great, 1872

on this head, 1859 1860 1861 1866
OMIT 1872

an organ as 1859 1860 1861 1866
the most 1872

as the eye. 1859 1860 1861 1866
organs. 1872

the colour of the skin and hair of quadrupeds, which, 1861 1866 1869 1872
which, from determining the attacks of insects or 1859 1860

or from determining the attacks of insects, might 1861 1866 1869 1872
might 1859 1860

— I
I
have sometimes felt as much difficulty, though of a very different kind, on this head, as in the case of an organ as perfect and complex as the eye.
In the first place, we are much too ignorant in regard to the whole economy of any one organic being, to say what slight modifications would be of importance or not. In a former chapter I have given instances of
very
most
trifling characters, such as the down on fruit and the colour of
the
its
flesh, the colour of the skin and hair of quadrupeds, which, from being correlated with constitutional
differences,
differences
or from determining the attacks of insects, might assuredly be acted on by natural selection. The tail of the giraffe looks like an artificially constructed fly-flapper; and it seems at first incredible that this could have been adapted for its present
pur- pose
purpose
by successive slight modifications, each better and
better
better,
fitted, for
for
so trifling an object as
to drive
driving
away flies; yet we should pause before being too positive even in this case, for we know that the distribution and existence of cattle and other animals in South America absolutely
depends
depend
on their power of resisting the attacks of insects: so that individuals which could by any means defend themselves from these small enemies, would be able to range into new pastures and thus gain a great advantage. It is not that the larger quadrupeds are actually destroyed (except in some rare cases) by
the
....
flies, but they are incessantly harassed and their strength reduced, so that they are more subject to disease, or not so well enabled in a coming dearth to search for food, or to escape from beasts of prey.
Organs now of trifling importance have probably in some cases been of high importance to an early progenitor, and, after having been slowly perfected at a