Some Experiments of L^uther Burbank 



prepotent and outweighs the original stock. Mon- 

 strosities produced by crossing often perpetuate 

 themselves as well as the species does." 



" One difficulty with the mutation theory of 

 Dr. De Vries, in my opinion, is lack of sufficient- 

 ly wide experimentation. Fuller investigations 

 will certainly show that the \ sports ' or ' chance ' 

 variations comes under the same law as that of 

 * fluctuating' variations, mutations being only 

 fluctuating variations carried beyond the critical 

 point where past fluctuating variations can not 

 withstand the accumulated forces without disinte- 

 gration, thus bending them in a new direction.'' 



Professor Hubrecht is certainly in error in 

 stating that the mean fluctuations can not be car- 

 ried into the extreme or * sport ' variations by 

 selection. Professor Hubrecht speaks of two diver- 

 gent processes, ' fluctuating variations ' and ' muta- 

 tions,' which he says: ' Darwin has not sufficiently 

 kept separate.' They are not separate; one is only 

 a tendency toward the other, and which continued, 

 though latent, may, or will, at last become domi- 



18 



