DARWIN'S THEORY. 21 



of breeding, Darwin infers from the Struggle for Exist- 

 ence which, he says, is, under nature, constantly carried 

 on, by all organisms, each with the others ; whereby 

 the weak succumb, and those which are the fittest, 

 strongest, and most vigorous survive. Besides the ; 

 selection of those which are the strongest, there will 

 also be a selection of those which display some new 

 modification ; and these mating with their fellow vic- 

 tors in the struggle for life, will attain, through their 

 offspring, to a higher and still higher development. 

 Conformably to the theory of Malthus, he contends, 

 that, under nature, the production of new organisms 

 far outruns the means of their subsistence ; that all 

 Nature is at war, one species with another, and the 

 individuals of the same species with each other. The 

 result of this Struggle 'for Existence, is Natural 

 Selection ; by which, the lucky and the stronger pre- 

 vail, and the weaker and ill-favored perish. As many 

 more individuals are born than can possibly survive, 

 those individuals which possess any variation which 

 contributes to give them an advantage in this warfare, 

 are, in the main, more likely to survive, to propagate, 

 and to occupy the places of their weaker brethren, 

 with their offspring. If but a single variation occurred 

 once in a thousand generations, says Darwin ; and that 

 variation were preserved by Natural Selection, until, at 

 the end of another thousand of generations, another 

 variation was superadded, the improvement and di- 

 versity of the species would, eventually, be such as to 

 occasion a divergence, by the different individuals fa- 

 vored, into distinct species. 



