| → 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 |
|
| → which, from determining the attacks of insects or 1859 1860 |
| the colour of the skin and hair of quadrupeds, which, 1861 1866 1869 1872 |
|
| → might 1859 1860 |
| or from determining the attacks of insects, might 1861 1866 1869 1872 |
|
|
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
trifling characters, such as the down on fruit and the colour of
flesh,
→which, from determining the attacks of insects or
from being correlated with constitutional
→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
by successive slight modifications, each better and
so trifling an object as
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
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
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
|
