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 



