102 CHARLES DARWIN. 



chapters deal partly with difficulties in the way of an 

 acceptance of organic evolution and partly with those 

 encountered by natural selection. 



Of the three remaining chapters before the XIV th, 

 and last, which contains the Recapitulation and 

 Conclusion, two— XI. and XII. — are concerned with 

 Geographical distribution, while the Xlllth deals with 

 Classification, Morphology, Embryology and Rudi- 

 mentary Organs. These three chapters are almost 

 entirely devoted to the proof that the facts of Nature 

 with which they deal are not inconsistent with, but 

 rather support, and often strongly support, a belief in 

 Organic Evolution. 



Hence we see that this, incomparably the greatest 

 work which the biological sciences have seen, begins 

 with an explanation and defence and definition of 

 the sphere of natural selection — then passes to con- 

 sider difficulties which are partly those of natural 

 selection, and partly of organic evolution — while it 

 finally treats of the evidences of the latter process 

 and the difficulties which a belief in it encounters. 



This arrangement was a very wise one for a book 

 which was intended to convince a large circle of 

 readers; for the human mind so craves after an 

 explanation, that it was of more importance for the 

 success of the work to show first that an intelligible 

 cause of evolution had been proposed, than to follow 

 the more logical order of first setting forth the 

 evidences of evolution. 



The second edition (fifth thousand) was issued in 



