58 THE THEORIES OF EVOLUTION 



runners, the works of Lamarck among others, who 

 attached much importance to other factors. 



At that time, A. R. Wallace, who originated simul- 

 taneously with Darwin, though independently of 

 him, the idea of natural selection, had already op- 

 posed this idea to Lamarck's conceptions. 



In his essays » (the first two written before he 

 could become acquainted with Darwin's theories, the 

 next under their direct influence), Wallace mentions 

 the life struggle and the survival of the fittest as the 

 only factors of evolution. Those essays are mostly 

 devoted to showing how natural selection could pro- 

 duce certain characters such as the protective col- 

 ouring and mimicry of animals. Never do we find 

 any other factors mentioned, even as being of second- 

 ary importance. 



Naturalists of the following generation exagger- 

 ^ ated (as scientists are apt to exaggerate every new 

 theory) , the role played by natural selection, a role 

 very different from that attributed to it by the au- 

 thor of the "Origin of Species." The Lamarckian 

 theories were discarded in their entirety; the direct ac- 

 tion of the environment on the organism and the 



i A R Wallace. Contribution to the Theory of Natural Selection, 

 1870 ' In the second essay entitled: On the Tendency of Varieties to 

 Depart indefinitely from the original Type, published in 1858, Wallace 

 expresses his ideas concerning natural selection. One of the chapter 

 heads in that essay reads: "Lamarck's hypothesis differs greatly from 

 that now advanced." 



