DARWINISM'S PRESENT STANDING. 379 



reaction against the selection theories. Thankfully accept- 

 ing the bricks and stones handed to them they have builded 

 Neglect of a house of great beauty : but with stones of 

 attention to the di ff erent s h ape a house of quite different ap- 



causes of varia- 

 tion, pearance might have been built. Is it not a 



cause for wonder that the selection masons have not been 

 more inquisitive concerning the whence and why of this 

 magical supply of just the needed sort of material at just the 

 right time? As a matter of fact, Darwin himself gave 

 serious attention to the origin of his always-ready varia- 

 tions, but his tremendous undertaking was too nearly super- 

 human already to permit him to add to it an adequate 

 attention to the problem of causes. But that same excuse 

 does not attach to his followers. And it is, I repeat, largely 

 this neglect to strive to penetrate the so-far unrent veil of 

 obscurity lying over the beginnings of species change that 

 has contributed to the growing revolt against the Allmacht 

 of the selection dogma. Who would in these days have a 

 following for his explanation of species origin must include 

 in his theory some fairly satisfying explanation of the first 

 visible beginnings of modification. 



Then, after the explanation of the why and how of varia- 

 bility, comes the necessity of explaining the cumulation of 

 this variability along certain lines, the first visi- 

 _ How is yam- j^ i ssuance o f these lines beins: as species, and 



tion cumulated ? 



later becoming more and more pronounced as 

 courses of descent. This explanation has got to begin lower 

 down in phyletic history than natural selection can begin. 

 Before ever there can be utility and advantage there must 

 have come about a certain degree of heaping up, of cumu- 

 lating, of intensifying variations. What are these factors? 

 They are possibly only two : ( I ) orthogenetic or deter- 

 minate variation as the outcome of plasm preformation or 

 of epigenetic influences, and (2) the segregation of similar 

 variations by physiologic or topographic conditions. Hence, 



