Seite - 213 - in The Origin of Species

UTILITARIAN DOCTRINE 213 one species had been formed for the exclusive good of an- other species, it would annihilate my theory, for such could not have been produced through natural selection. Although many statements may be found in works on natural history to this effect, I cannot find even one which seems to mc of any weight. It is admitted that the rattlesnake has a poison- fang for its own defence, and for the destruction of its prey; but some authors suppose that at the same time it is furnished with a rattle for its own injury, namely, to warn its prey. I would almost as soon believe that the cat curls the end of its tail when preparing to spring, in order to warn the doomed mouse. It is a much more probable view that the rattlesnake uses its rattle, the cobra expands its frill, and the puff-adder swells whilst hissing so loudly and harshly, in order to alarm the many birds and beasts which are known to attack even the most venomous species. Snakes act on the same principle which makes the hen ruffle her feathers and expand her wings when a dog approaches her chickens ; but I have not space here to enlarge on the many ways by which animals endeavour to frighten away their enemies. Natural selection will never produce in a being any struc- ture more injurious than beneficial to that being, for natural selection acts solely by and for the good of each. No organ will be formed, as Paley has remarked, for the purpose of causing pain or for doing an injury to its possessor. If a fair balance be struck between the good and evil caused by each part, each will be found on the whole advantageous. After the lapse of time, under changing conditions of life, if any part comes to be injurious, it will be modified; or if it be not so, the being will become extinct as myriads have become extinct. Natural selection tends only to make each organic being as perfect as, or slightly more perfect than, the other inhabi- tants of the same country with which it comes into competi- tion. And we see that this is the standard of perfection attained under nature. The endemic productions of New Zea- land, for instance, arc perfect one compared with another; but they arc now rapidly yielding before the advancing le- gions of plants and animals introduced from Europe. Natural selection will not produce absolute perfection, nor do wc