Origin of Species Variorum

→ the most 1872

an organ as 1859 1860 1861 1866

→ organs. 1872

as the eye. 1859 1860 1861 1866

→ 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

→ to existing species in 1869 1872

in 1859 1860 1861 1866

→ would of course 1872

will always 1859 1860 1861 1866

will of course 1869

→ case of the dog, 1872

dog, 1859 1860 1861 1866 1869

→ in this latter respect must 1869 1872

must 1859 1860 1861 1866

→ still more quickly. 1872

quickly enough. 1859 1860 1861 1866 1869

→ easily err in 1872

sometimes 1859 1860 1861 1866 1869

→ and in believing that they have been developed through 1872

which are really of very little importance, and which have originated from quite secondary causes, independently of 1859 1860 1861 1866

which have originated from quite secondary causes, independently of 1869

of →the most perfect and complex →organs.

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

most

very

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

for

fitted, for

so trifling an object as

driving

to drive

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 former period, have been transmitted →to existing species in nearly the same state, although now

become

....

of very slight use;

and

but

any actually injurious deviations in their structure →would of course have been checked by natural selection. Seeing how important an organ of locomotion the tail is in most aquatic animals, its general presence and use for many purposes in so many land animals, which in their lungs or modified swimbladders betray their aquatic origin, may perhaps be thus accounted for. A well-developed tail having been formed in an aquatic animal, it might subsequently come to be worked in for all sorts of

purposes,

purposes,—

as a fly-flapper, an organ of prehension, or as an aid in turning, as

with

the →case of the dog, though the aid →in this latter respect must be slight, for the hare, with hardly any tail, can double →still more quickly.

In the second place, we may →easily err in

attribute

wrongly attribute

attributing

importance to

characters

characters,

→and in believing that they have been developed through