376 DARWINISM TO-DAY. 



fitness. Modification and development may have been 

 proved to occur along determinate lines without the aid of 

 natural selection. I believe they have. But such develop- 

 ment cannot have an aim ; it cannot be assumed to be 

 directed toward advance ; there is no independent progress 

 upward, i. e., toward higher specialisation. At least, there 

 is no scientific proof of any such capacity in organisms. 

 Natural selection * remains the one causo-mechanical ex- 

 planation of the large and general progress toward fitness ; 

 the movement toward specialisation ; that is, descent as we 

 know it. 



But what Darwinism does not do is to explain the begin- 

 nings of change, the modifications in indifferent characters 

 An explanation and in indifferent directions. And all this is 

 of cntn g \ g is ningS tremendously important, for there are among 

 needed, animals and plants hosts of existent indifferent 



characters, and many apparently indifferent directions of 

 specialisation. As to the obvious necessity of beginnings 

 nothing need be said. What is needed, then, is a satisfactory 

 explanation of the pre-useful and pre-hurtful stages in the 

 modifications of organisms : an explanation to relieve Dar- 

 winism of its necessity of asking natural selection to find 

 in the fluctuating individual variations a handle for its 

 action ; an explanation of how there ever comes to be a 

 handle of advantage or disadvantage of life-and-death- 

 determining degree. With such an explanation in our 

 possession and whether any one or more of the various 

 theories proposed to fill this need, such as Eimerian 

 orthogenesis, de Vriesian heterogenesis, Rouxian battle of 

 the parts, or Weismannian germinal selection, etc., give 

 us this explanation, may be left for the moment undebated 

 with such a satisfactory explanation, I say, once in our 

 hands, we may depend with confidence on natural selection 

 to do the rest of the work called for by the great theory 

 of descent. Among all the divergent lines of development 



