gS A Factor in Evolution 



tral brain connections, and is a slight variation for func- 

 tional purposes at the best, the hypothesis of use-inheri- 

 tance becomes not only unnecessary, but to my mind quite 

 superfluous' (above, Chap. V.). For adaptations gener- 

 ally, • the most plastic individuals will be preserved to do 

 the advantageous things for which their variations show 

 them to be the most fit, and the next generation will show 

 an emphasis of just this direction in its variations' (from 

 an earlier page). 



We get, therefore, the principle, that individual accom- 

 modations may keep a species afloat with certain results 

 in the sphere of phylogeny — the whole constituting the 

 principle of Organic Selection. 



I. // results that there arise by survival certain lines of 

 deteniiinate'^ pJiylogenctic cJiange in the directions of the de- 

 terminate ontogenetic accommodations of the earlier genera- 

 tions. The variations which have been utilized for onto- 

 genetic accommodation in the earlier generations, being 

 thus kept in existence, are utilized more widely in the sub- 

 sequent generations. ' Congenital variations, on the one 

 hand, are kept alive and made effective by their use for 

 adjustments in the life of the individual ; and, on the other 

 hand, adaptations become congenital by further progress 

 and refinement of variation in the same lines of function 

 as those which their acquisition by the individual called 

 into play. But there is no need in either case to assume 

 the Lamarckian factor' (from an earlier page). In cases of 

 conscious adaptation: 'We reach a point of view which 

 gives to organic evolution a sort of intelligent direction 



^ The phrase ' determinate change ' here is merely descriptive, meaning 

 change in lines which keep to a definite direction. See the further discussion 

 of the term 'determinate' below, Chap. XII. § I. 



