418 ORIGINATIVE FACTORS IN EVOLUTION: 



and perhaps they are pedantically right: the distinction is 

 one of common sense. There is many a grade between those 

 who find their fingers indispensable in simple computations, 

 and the calculating boy who can tell us in a few seconds the 

 cube root of 2,498,846,293 yet cannot explain how he knows, 

 but there seems good sense in recognising the latter as a 

 qualitative change. So with the mathematical genius, the 

 musical genius, the artistic genius, and there is not any rea- 

 son to believe that Man is the only species that produces 

 geniuses. The evidence of their occurrence elsewhere is in 

 the rapidly-growing records of mutations of large amount. 

 There is a mutation-theory, but is there any theory of muta- 

 tions ? 



On the dark problem of the origin of the distinctively 

 new some beams of light have been shed. (1) First, there 

 '' are facts suggesting that deeply saturating environmental 

 influences may act as variational stimuli on the germ-cells 

 and provoke change. Professor MacDougal injected solu- 

 tions of sugar and compounds of calcium, potassium, and zinc 

 into the developing ovaries of one of the Evening Primroses, 

 and got out of several hundreds of seeds sixteen individuals 

 notably atypical, which bred true to the second and third 

 generation. There were not only losses and augmentations, 

 there were well-marked novelties which maintained their 

 distinctiveness when crossed with the parental strains. It 

 should be noted that what Professor MacDougal injected was 

 not very much out of the way, and might be paralleled by nat- 

 ural changes in the chemical composition of the sap of the 

 plant. Professor Punnett expresses the view of many natural- 

 ists when he says : " There is reason to suppose that environ- 

 mental change leads to abnormal divisions in the ripening 

 germ-cells, and that these abnormal divisions are the starting- 



