CiiAP. IV. NATURAL SELECTION. 85 



to each beinp^ in the frrcat and complex battle of life, sliouUl 

 sometimes occur in the course of thousands of generations? 

 If such do occur, can we doubt (remembering' that many more 

 individuals are born than can possibly survive) that individuals 

 having any advantage, however slight, over others, would have 

 the best chance of surviving and of procreating their kind ? 

 On the other hand, we may feel sure that any variation in the 

 least degree injurious would be rigidly destroyed. This pres- 

 ervation of favorable variations, and the destruction of injuri- 

 ous variations, I call Natural Selection, or the Survival of the 

 Fittest. Variations neither useful nor injurious would not be 

 affected by natural selection, and would be left either a fluc- 

 tuating element, as perhaps we see in certain polymorphic 

 species, or would ultimately become fixed, owing to the nature 

 of the organism and the nature of the conditions. 



Several writers have misapprehended or objected to the 

 tenn Natural Selection. Some have even imagined that nat- 

 ural selection induces variability, whereas it imphes only the 

 preservation of such variations as occur and are beneficial to 

 the being under its conditions of life. No one objects to agri- 

 culturists speaking of the potent effects of man's selection ; and 

 in this case the individual differences given by Nature, which 

 man for some object selects, must of necessity first occur. 

 Others have objected that the term selection implies conscious 

 choice in the animals Avhich become modified; and it has even 

 been urged that, as plants have no volition, natural selection is 

 not applicable to them ! In the literal sense of the word, no 

 doubt, natural selection is a false term ; but who ever objected 

 to chemists speaking of the elective affinities of the various 

 elements ? — and yet an acid cannot strictl}^ be said to elect the 

 base with which it in preference combines. It has been said 

 that I speak of natural selection as an active power or Deity ; 

 but who objects to an author speaking of the attraction of 

 gravity as ruling the movements of the planets ? Every one 

 knows what is meant and is implied by such metaphorical ex- 

 ])ressions ; and they are almost necessary for brevity. So, 

 again, it is difficult to avoid personifying the word Nature ; but 

 I mean by Nature, only the aggregate action and product of 

 many natural laws, and by laws the sequence of events as as- 

 certained by us. With a little familiarity such superficial ob- 

 jections Avill be forgotten. 



We shall best understand the probable course of natural 

 selection by taking the case of a country undergoing some 



