III. 



Individual Variations. 



IN a Note with the heading " Variation and Probability " in 

 Natural Science (vol. vi., p. 217) it is said :— " There are two 

 classes of variation," viz., " large or sports," and " numerous small 

 variations." ..." Have species come from the large or from 

 the small variations ? " I am inclined to answer — rarely from either 

 or chiefly from neither. Mr. Wallace expresses himself somewhat 

 differently, for he says l : — " In securing the development of new 

 forms in adaptation to the new environment, Natural Selection is 

 supreme. Hence arises the real distinction, though we may not 

 always be able to distinguish them, between specific and non- 

 specific or developmental characters. The former are those definite, 

 though slight, modifications through which each new species actually 

 became adapted to its changed environment. They are, therefore, in 

 their very nature useful. The latter are due to the laws which 

 determine the growth and development of the organism, and, there- 

 fore, rarely coincide exactly with the limits of a species." 



Mr. Wallace here leaves " sports " out of consideration altogether, 

 but separates the " definite," i.e., the adaptive characters or varia- 

 tions, out of the numerous " indefinite," ill-adapted, or injurious 

 variations (which he also omits to mention), which, according to 

 Darwinism, Natural Selection has eliminated. 



So that we have the following groups of variations : — 



1. " Large and striking variations or sports " (writer in Natural 

 Science). 



2. " Numerous small " (writer in Natural Science), i.e., the 

 same as the " developmental or non-specific characters " (Wallace). 

 These I will call " Individual variations." 



3. " Adaptive or definite characters " of true varieties and 

 species (Wallace and myself). 



4. Ill-adapted, or useless, or injurious, or " indefinite " variations, 

 eliminated by Natural Selection (Darwinism). 



As far as plants are concerned I would suggest instead the three 

 following groups : — 



1. Sports, occurring mainly under cultivation, and probably 

 rarely supplying the source of varieties and species in nature. 



1 Fortnightly Review, March, 1895, p. 444. 



