Natural Selection is the manuscript on which Darwin based his landmark volume, On the Origin of Species.This edition, first published in 1975 and now available in paperback, presented, for the first time, the complete work; a formal and thorough presentation of Darwin's views on evolution. Compared with the Origin, the original long work on Natural Selection has more abundant examples and illustrations of Darwin's argument, plus an extensive citation of sources and references, which were totally absent from The Origin of Species. Professor Stauffer has edited Darwin's manuscript with meticulous care, without departing from Darwin's own words, to make the lengthy text as readable as possible, clarifying Darwin's source of citations and explaining the interrelationship of this work with other papers and published material.