222)

Sect VI. Characters of little importance

one is of special use to them; we cannot believe that the presence of the same bones in the arm & hand of the monkey, in the leg & foot of the dog, in the wing of the bat & fin flipper of the seal, are of special use to these animals. They are due to inheritance. But the webbed feet of the parent the ancestors ancestor of the upland goose & of the frigate-birds, webbed feet no doubt were as useful to them, as to as they now are to the most aquatic of existing birds; so again we may believe that the structures of the li bones of the limbs of the common ancestor of the monkey, dog, bat & seal &c was at that utterly remote period of use to it; & was produced by natural selection, subjected formerly as now to the laws of inheritance, variation & correlations of growth. Hence almost every detail of structure of every living creature, (making some little allowance for the direct action of physical conditions) must may be viewed either as having been directly of use to its ancestors or to itself at some ancestral form or as being, now of use to the being at present day; either directly, or indirectly through the complex laws of reversion & correlation of growth.

Natural selection cannot possibly produce any modification in one species for exclusively for the good of another species; though throughout nature one species incessantly takes

(223

Sect VI. What selection can do

advantage of & profits by above character the structures of another. (a) If it could be found that modifications of one form species for the exclusive good of another form species, had do exist, it would annihilate our theory; for such could not have been produced through natural selection.

Although many facts statements may be found in works on natural history to this effect, I cannot find even one which seems to me of any weight.

It is admitted that the poison-fang of a rattle-snake is given to it for defence & for the destruction of its prey, but some suppose that it has at the same time a rattle to warn its prey: I would as soon believe that the cat curls the end of its tail, when preparing to spring, to warn the doomed mouse. But I have not space here to enter on this or other such cases.

Natural selection will never produce anything injurious for a being, for it acts solely by & for the good of each. No organ will be found, as Paley has remarked, to cause for the purpose of causing pain or doing injury to its possessor. If a fair balance be struck, between the good & evil caused by

[223 insert]

(a)

But natural selection can & does often, produce structures for the good of the owner but for the direct injury of others species, - as the sting of the wasp, or the ovipositor of the chneumon, by which eggs are deposited in the living bodies of other animals.

(224

Sect VI. What selection can do

each part, each will be found on the whole advantageous. After the lapse of time, under changing conditions, if any part comes to be injurious, it will be modified, or the organism being will become, as myriads have become, extinct.

Natural selection tends only to make each organism as perfect as, or slightly more perfect than, the other inhabitants of the same country, with which it has to struggle for existence. And we see that this is so in nature. The endemic productions of New Zealand, for instance, are perfect one compared with another; but by universal concurrent testmony they are rapidly yielding to before the advancing legions of introduced European plants & animals. Natural selection will not produce absolute perfection; nor apparently do we meet with it in nature. The correction for aberration is said on high authority not to be perfect even in that most perfect organ the eye. If our reason forced leads us to admire with enthusiasm a multitude of inimitable contrivances in nature; this same reasons tell us,

(269

Sect 7. Instinct

standing in connection relation with an an imperfect condition of the male sex; for in bullocks of some breeds have horns much proportionally longer than in other breeds, in comparison with than those of the perfect bull or cow. Hence I can see no real difficulty in any peculiarity becoming correlated with the sterile condition of social insects: the difficulty lies in seeing how such correlated modifications of structure could have been slowly accumulated in any profitable direction by means of natural selection.

This difficulty, though appearing at first insuperable, is lessened, or as I believe disappears, when it is [text excised] that selection may be applied to the family, as well as to the individual, & may thus gain the desired end. Thus a well flavoured vegetable is cooked & is of fine flavour& the individual is destroyed; but the horticulturalist sows seed of the same stock & confidently expects to get nearly the same variety: breeders of cattle wish the flesh & fat to be well marbled together, the slaughtered animal which has has been slaughtered; this meat cannot breed propagate its Kind, but the breeder goes with confidence to the same family. & confidently expects there to get the desired character. I have such confidence faith in the powers of selection, that I do not doubt by wa carefully watching which individuals bulls & cows when matched produced

271

Sect 7. Instinct

quite unknown: in the Mexican Myrmecocystus, one caste of the workers of one cast never leave the nest, are fed by the other workers, & have an enormously developed abdomen which secretes a saccharine fluid sort of honey, for the other ants, & this which seems to supply the place of that excreted by the aphides, or the domestic cattle as they may be called which our aphides European ants Keep at guard or imprison.

It may will indeed be thought that I have an overweening confidence in the principle of natural selection, when I do do don't can not at once admit that such wondrous & well established facts do not at once annihilate my theory. Recurring to the simpler [text excised] of a neuter insects all of the same kind & all rendered ren [text excised] made by natural selection [text excised] fertile males & females; analogy would lead me to suppose that any slight profitable modifications would at first be transmitted not to all the neuters in the same nest, but to some alone; but that for by the long continued selection of the parents which produced some such neuters, all the neuters would finally ultimately come to have the desired profitable desired or profitable peculiarity modification. Hence on this view we ought we might expect to find cases of neuter insects of the same species & in the same nest, presenting gradations of structure; & this we often do find, even often find considering how few neuter insects out of Europe have been examined carefully examined. Mr F. Smith has shewn (& I have made many measurements) how surprisingly