NATURAL SELECTION V. ADAPTATION. 



79 



I sum up now the erroneous features of "Darwinism." I would 

 enumerate them as follows : 



First, by adding "structure" to Malthus' theory he introduced an 

 element which had nothing to do with it. 



Secondly, by making " individual differences " a basis for natural' 

 selection, he adopted a source as a general rule quite incapable of the 

 results expected. He was misled by assuming the numerous differences 

 which occur under cultivation (as, e.g., the hundreds of Sweet Peas &c.) 

 to be imitated in nature, where, however, they do not occur. 



Thirdly, he assumed that when plants and animals were placed under 

 changed conditions of life the offspring grew up varying "indefinitely," 

 so that only such as " happened " to be suitable survived. Hence there 

 was no natural laic connecting the favourable variations with the future 

 requirements of the organism.* 



Part II. — Adaptation, or the True Darwinism. 



In dealing with this alternative to natural selection, I go to Darwin 

 again ; for he laid the foundation himself of the true method of Evolution, 

 but without knowing it, in what he called " Definite Variation." The- 

 following passage will explain what he meant : — "If we ask ourselves 

 why this or that character has been modified under domestication, we 

 are, in most cases, lost in utter darkness. Many naturalists, especially 

 of the French school, attribute every modification to the 'monde ambiant,' 

 that is, to a changed climate, with all its diversity of heat and cold, 

 dampness and dryness, light and electricity, to the nature of the soil and 

 to varied kinds and amount of food. By the term definite action I mean 

 an action of such a nature that when many individuals of the same 

 variety are exposed during several generations to any change in their 

 physical conditions of life all, or nearly all, the individuals are modified 

 in the same manner. A new sub-variety would thus be produced without 

 the aid of natural selection." f 



Darwin, however, thought this to be very exceptional ; for he says : 

 " I will give in detail all the facts which I have been able to collect, 

 rendering it probable that climate, food, &c. have acted so definitely and 

 powerfully on the organisation of our domesticated productions that they 

 have sufficed to form new sub-varieties or races without the aid of 

 selection by man or of natural selection." The reader must be referred to 

 the detailed account in the work itself ; % but it may be mentioned here 

 that he gives seven kinds of flowers, three of variegated leaves, about 

 fifteen of vegetable products, four of fruits, three of woods, and five of 

 diseases (which, of course, have nothing to do with evolution or the 

 origin of species). The above was published in 1868. However, in 1876 



* It is an interesting fact that Darwin never foresaw the effect of this theory upon 

 certain of his followers. He said : — " The birth both of the species and of the individual 

 are [sic] equally parts of that grand sequence of events which our minds refuse to 

 accept as the result of blind chance " (Descent of Man, ii. p. 395). 



Haeckel says : — " Darwin gave us the key to the monistic explanation. Mechanism 

 alone can give us a true explanation of natural phenomena. For it traces them to 

 their efficient causes, viz. to blind and unconscious agencies" (The Riddle of the 

 Universe, pp. 264, 265). 



f An. and PL under Dom. ii. p. 271. % An. and PL under Dom. ii. p. 281. 



