PEEFACE. 



T~N the Study of Evolution progress had well- 

 -- nigh stopped. The more vigorous, perhaps also 

 the more prudent, had left this field of science 

 to labour in others where the harvest is less pre- 

 carious or the yield more immediate. Of those who 

 remained some still struggled to push towards truth 

 through the jungle of phenomena: most were content 

 supinely to rest on the great clearing Darwin made 

 long since. 



Such was our state when two years ago it was 

 suddenly discovered that an unknown man, Gregor 

 Johann Mendel, had, alone, and unheeded, broken off 

 from the rest in the moment that Darwin was at 

 work and cut a way through. 



This is no mere metaphor, it is simple fact. Each 

 of us who now looks at his own patch of work sees 

 Mendel's clue running through it : whither that clue 

 will lead, we dare not yet surmise. 



It was a moment of rejoicing, and they who had 

 heard the news hastened to spread them and take the 



