460 Evolution and Adaptation 



with their value, does not this in the end amount to nearly 

 the same thing as maintaining that evolution of organisms 

 has been a steady progress forward, — a progress undirected 

 by external forces, but the outcome of internal development ? 

 Admitting that innumerable creations have been lopped off, 

 because they could find no foothold, yet, as Nageli points out, 

 the result is that, instead of a dense tangle of forms, there 

 has been left relatively few that have been found capable of 

 existing, — those that have found some place in which they 

 can live and leave progeny. From this point of view it 

 may appear, at first thought, that the idea of evolution 

 through mutations involves a fundamentally different view 

 from that of the Darwinian school of selection ; but in so far 

 as selection also depends on the spontaneous appearance of 

 fluctuating variations, the same point of view is to some ex- 

 tent involved, — only the steps are supposed to be smaller. 

 This point is usually ignored and passed over in silence by 

 the Darwinians, but, as Wigand has pointed out, it makes 

 very little difference whether the stages in the process of 

 evolution are imagined to be very small or somewhat larger, 

 so long as they are spontaneous. Selection does not do more 

 than determine the survival of what is offered to it, and does 

 not create anything new. 



It is true that if the fluctuating variations that are selected 

 be connected by very slight differences with an almost con- 

 tinuous series of other forms, and if little by little such a 

 series be advanced in a given direction by selection, we get 

 the idea of a continuity, whose advance is determined by selec- 

 tion. It is this conception that appears to give the theory of 

 natural selection a creative power, which in reality it does 

 not possess, and certainly not in the modified form in which 

 the theory was finally left by Darwin. For Darwin found 

 himself forced to admit that, unless a very considerable num- 

 ber of individuals varied at the same time and in the same 

 direction, the formation of new species could not take place, and 



