276 THE ORIGIN OF SPECIES 



CHAPTER XV 



RECAPITULATION AND CONCLUSION 



Recapitulation of the objections to the theory of Natural SelectiOD — Ro- 

 capitulation of the general and special circumstancea in its fh,yot — 

 Causes of the general belief in the immutability of species — How iar the 

 theory of Natural Selection may be extended — Efifects of ita atdoptioa 

 on the study of Natural History — Concluding remarks 



AS THIS whole volume is one long argumeat, it 

 may be convenient to the reader to have the 

 leading facts and inferences briefly recapitulated. 

 That many and serious objections may be advanced 

 against the theory of descent with modification through 

 variation and natural selection, I do not deny. I have 

 endeavored to give to them their full force. Nothing 

 a t first can appear more difficult to believe than that the 

 more complex organs and instincts have been perfected, 

 not by means superior to, though analogous with, human 

 reason, but by the accumulationo f innumerable slig hf 

 variations, each good for the individual possesso r. Nev- 

 ertheless, this difficulty, though appearing to our imag- 

 ination insuperably great, cannot be considered real if 

 we admit the following propositions, namely, that all 

 parts of the organization and instincts offer, at least, 

 individual differences — that t here is a struggle f or ex - 

 i stence leading to the preservation of ^ profitable devja- 

 tions of structure or instinct — and, lastly, that gradations 



