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CHAPTER XXI. 



VARIATION OF ANIMALS AND PLANTS UNDER DOMESTI- 

 CATION : PANGENESIS (1868). 



We now come to consider the succession of invaluable 

 works produced by Darwin after the appearance of the 

 "Origin," the last of which — that on Earthworms — 

 was published about six months before his death. 



Darwin's method of bringing these results before 

 the world was somewhat diiferent from that most 

 generally adopted by scientific men in this country, 

 although of common occurrence in Germany. The 

 great majority of scientific facts are here published by 

 the proceedings or transactions of scientific societies, 

 or in special journals ; and although a scientific man 

 frequently brings together his general results into a 

 volume for the public, the original communications 

 remain as the detailed exposition of his researches. 



Darwin, too, wrote a very large number of memoirs 

 for the scientific societies, as may be seen from the list 

 in Appendix III. of the " Life and Letters," but the 

 volumes which he subsequently published included 

 all the previous details, with the addition of much 

 new matter, and it is these volumes rather than the 

 original communications which form the authoritative 

 statement of his investigations. Such a method was 



