50 HEREDITY 



frequency of variation, or the fact that it so con- 

 stantly accompanies heredity, but pre-eminently 

 because of the supremely important role of varia- 

 tions. As Bateson says of heredity and variation : 

 " Every one knows that, somewhere hidden among 

 the phenomena denoted by these terms, there must 

 be principles which, in ways untraced, are ordering 

 the destinies of living beings." Without variations, 

 natural selection would have no material upon 

 which to work. Even when we limit the term, as is 

 done throughout these chapters, to mean what are 

 sometimes distinguished as blastogenic variations, 

 those true variations which have their seat in the 

 germ, we must recognise that without variation there 

 could be no evolution. 



What, then, is the origin of true variations : 

 " spontaneous " or " germinal " or " blastogenic " 

 variations ? 



We are long past the days when it was possible 

 to speak of heredity and variation as opposing 

 " forces " or " principles." These are good words 

 in their place ; out of their place they merely cloak 

 ignorance. Also, we cannot be satisfied by explaining 

 variation in accordance with that amusing piece of 

 nonsense known as the Bathmic ^ theory of organic 

 evolution, which attributes it to an " inherent adap- 

 tive growth-force." Nor have we any use to-day 

 for the hypothesis that variations are unique 

 amongst phenomena in being outside the law of 

 universal causation ; that they are directly due to 

 the designing volition of a Divine Person. If all 

 rational explanations fail us, we must not content 



1 From the Greek bathmis, a step. 



