The Making of Species 



tion is practically nil. We do not even know 

 along what particular lines mutations occur. 



We have yet to discover whether one mutation 

 invariably leads to another along the same lines 

 in other words, whether mutating organisms 

 behave as though they had behind them a force 

 acting in a definite direction. The solution of 

 these problems seems afar off. The hope of 

 solving them lies, not in the speculations in 

 which biologists of to-day are so fond of in- 

 dulging, but in observation and experiment, 

 especially the last. 



The future of biology is largely in the hands 

 of the practical breeder. 



388 



