10 THE EVOLUTION OF PLANTS 



tion, any more than that of his predecessors, 

 nor have exercised the vast influence which it 

 has done on the thought of the world. 



When the theory now known as Darwinism 

 was first made public, on July 1, 1858, the title 

 of the joint papers by Darwin and Wallace, 

 then read before the Linnean Society, was: "On 

 the tendency of Species to form Varieties, and 

 on the Perpetuation of Varieties and Species by 

 Natural Means of Selection." When Darwin's 

 "Abstract" of his theory appeared in the follow- 

 ing year it bore the title: "On the Origin of 

 Species by means of Natural Selection or the 

 Preservation of favoured Races in the Struggle 

 for Life." The essential feature of the Darwin- 

 ian theory is the selection, by natural means, 

 of such variations as are advantageous to the 

 plant or animal concerned. To quote Darwin's 

 words: "As many more individuals of each 

 species are bora than can possibly survive; and 

 as, consequently, there is a frequently recurr- 

 ing struggle for existence, it follows that any 

 being if it vary however slightly in any manner 

 profitable to itself, under the complex and some- 

 times varying conditions of life, will have a better 

 chance of surviving, and thus be naturally selected. 

 From the strong principle of inheritance, any 

 selected variety will tend to propagate its new 

 and modified form" (Origin of Species, p. 3). 



