68 CHARLES DARWIN. 



before he received Wallace's essay. A tolerably full 

 abstract of the- letter, which is itself a very brief 

 abstract, is therefore printed below. The epitome 

 here given is taken from the letter itself, and is in 

 certain respects more full than that published in the 

 Linnean Journal. 



In the introductory parts Darwin explained that 

 " the facts which kept me longest scientifically 

 orthodox are those of adaptation the pollen-masses 

 in asclepias the mistletoe, with its pollen carried by 

 insects, and seed by birds -the woodpecker, with its 

 feet and tail, beak and tongue, to climb the tree and 

 secure insects. To talk of climate or Lamarckian 

 habit producing such adaptations to other organic 

 beings is futile. This difficulty I believe I have 

 surmounted." Having then stated that the reasons 

 which induced him to accept evolution were " general 

 facts in the affinities, embryology, rudimentary organs, 

 geological history, and geographical distribution of 

 organic beings," he proceeds to give a brief account 

 of his " notions on the means by which Nature 

 makes her species." The following is an abstract of 

 the account he gives: 



1. The success with which selection has been applied by 

 man in making his breeds of domestic animals and plants : 

 and this even in ancient times when the selection was uncon- 

 scious, viz. when breeding was not thought of, but the most 

 useful animals and plants were kept and the others destroyed. 

 "Selection acts only by the accumulation of very slight or 

 greater variations," and man in thus accumulating " may be 

 said to make the wool of one sheep good for carpets, and 

 another for cloth, &c." 



