252 Heredity and Eugenics 



or cause driving organisms toward a series of goals, which, 

 when passed, represent the final goal of that particular race. 

 If this conception were true, then there would exist in 

 organisms a state totally unlike that found elsewhere in 

 nature. In no physical or chemical phenomena does any 

 such condition exist, but rather, an array of substances 

 which can be combined and recombined in an almost infinite 

 series of combinations, which can be built up to complex 

 aggregations and with equal facility reduced down to the 

 atomic groups from which they came. In other words, 

 by a selective synthetic process it is possible to create or 

 synthetize, and likewise, by a selective analytical process 

 to analyze, and the irreversibility of evolution exists only 

 in the dogmatism of some essayists, and not in the 

 materials of nature. 



To what extent the selective process is operative in the 

 production of variation in nature is unknown. It is not 

 probable that in nature there would exist the arrangement 

 of variations which I brought about in experiment, but in 

 nature I should rather look for a very decidedly haphazard 

 process, bringing about chance combinations which would 

 produce this or that result, and these chance combinations 

 might any two of them combine and produce a third chance 

 combination which would stand apart from the parent 

 species — the product of the two others, but if found in 

 nature it would be described as a "mutation." What role 

 these variations, and I am convinced that they are potent 

 factors in evolution, really would have in the general evolu- 

 tion of organisms and in the development of species, is un- 

 known. It is not inconceivable that a variation might 

 thus arise which, behaving as a strong dominant or as a 

 dominant heterozygote, could increase in numbers and 



