332 DARWINISM TO-DAY. 



with the broader base, so to speak, with the inherited 

 tendency to remain unshaken by the modifications of the 

 environment, may be conceived as through this tendency 

 to be and to remain less injuriously affected by adverse 

 circumstances, and consequently might still endure. In 

 short, natural selection in the one case would find its ful- 

 crum in the tendency to easy adjustment of characters; and 

 in the other case in the inherited persistency in equilibrium 

 rendering its possessor more or less indifferent to the in- 

 jurious elements of the environment. The intermediate 

 individuals by the hypothesis would be those least-fitted to 

 persist in any case and hence liable to be rapidly eliminated. 

 Then we should have parallel series of species in two or even 

 more genera existing simultaneously/' 



Francis Galton, the great student of heredity and, in most 



of his belief a thorough Darwinian, nevertheless held it to be 



probable that evolution might proceed not only 



G-alton's belief by minute steps but that decisive sudden changes 



in discontinuous f . 



01 toe type may occur. 1 hat the steps may 



be small and that they must be small are very 

 different views; it is only to the latter that I object, and 

 only when the indefinite word 'small' is used in the sense of 

 'barely discernible' or as small compared with such large 

 sports as are known to have been the origin of new races." ' 

 And his familiar analogy of organic stability to that of the 

 polygon 9 with unequal sides, whose stability or fixity de- 

 pends upon which of these sides it may be resting on, ex- 

 presses well the basic idea in heterogenesis or mutation by 

 small but definitive and fairly stable changes. Galton also 

 believed in the stability or fixity of sports ; not that all trans- 

 mit their character to their young but that many do and thus 

 give rise to new types. 



Emery, 10 in his suggestive paper called "Gedanken zur 

 Descendenz- und Vererbungstheorie," expresses his belief 

 in the importance in species-forming of what he calls "pri- 



