104 DAKWINISM STATED BY DARWIN HIMSELF. 



me of any weight. It is admitted that the rattlesnake 

 has a poison-fang for its own defense, and for the de- 

 struction of its prey ; but some authors suppose that at 

 the same time it is furnished with a rattle for its own in- 

 jury, namely, to warn its prey. I would almost as soon 

 believe that the cat curls the end of its tail when prepar- 

 ing 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 while 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 feath- 

 ers 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 endeavor to frighten away 

 their enemies. 



Natural selection will never produce in a being any 

 structure 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 pos- 

 sessor. 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 inhabitants of the same country with which it comes 

 into competition. And we see that this is the standard 

 of perfection attained under nature. The endemic pro- 

 ductions of New Zealand, for instance, are perfect one 



