Individual Accommodation on Evolution 97 



tant series of facts recently brought to light are those 

 which show what is called ' determinate evolution ' from 

 one generation to another. This has been insisted on by 

 the paleontologists. Of the two current theories of hered- 

 ity, Neo-Lamarckisrn, by means of its principle of the 

 inheritance of acquired characters, has been better able 

 to account for this fact of determinate phylogenetic change. 

 Weismann admits the inadequacy of the principle of 

 natural selection, as operative on rival organisms, to 

 explain variations when they are wanted, or, as he puts 

 it, * the right variations in the right place ' (Monist, Janu- 

 ary, 1896). 



It is argued in the preceding pages, that the determinate 

 modifications of function in ontogenesis, brought about by 

 neuro-genetic and psycho-genetic accommodation, do away 

 with the need of appealing to the Lamarckian factor. In 

 the case, e.g., of instincts, 'if we do not assume con- 

 sciousness, then natural selection is inadequate; if we 

 do assume consciousness, then the inheritance of acquired 

 characters is unnecessary ' (from an earlier page). ' The in- 

 telligence which is appealed to, to take the place of instinct 

 and to give rise to it, uses just those partial variations 

 which tend in the direction of the instinct ; thus the intelli- 

 gence supplements such partial coordinations, makes them 

 functional, and so keeps the creature alive. This prevents 

 the 'incidence of natural selection.' So the supposition 

 that intelligence is operative turns out to be just the sup- 

 position which makes use-inheritance unnecessary. Thus 

 kept alive, the species has all the time necessary to per- 

 fect the variations required by a complete instinct. And 

 when we bear in mind that the variation required is not 

 on the muscular side to any great extent, but in the cen- 

 H 



