VI 



PREFACE. 



essay in the " Nature Series " with such 

 additions and alterations as appear to me, on 

 second thoughts, to be desirable. The only 

 object of the essay is that which is expressed 

 in the opening paragraph. 



London, 



June i, 1882. 



SINCE this little Essay was published, it has been 

 suggested to me that, in its mode of presenting 

 the arguments in favour of Evolution, there is a 

 similarity to that which has been adopted by 

 Mr. Herbert Spencer in the third part of his 

 Principles of Biology. I should therefore like to 

 state, that while such similarity is no doubt in 

 part due to the similarity of subject-matter, I 

 think, upon reading again, after an interval of ten 

 years, his admirable presentation of the evidence 

 it may also in part be due to unconscious 

 memory. This applies particularly to the headings 

 of the chapters, which I find to be almost identical 

 with those previously used by Mr. Spencer. 



G. J. R. 



