110 Elementary Species 



appeared some years later at the International | 



Exhibition of London in 1862. Hence, when- 

 ever Darwin speaks of selection, Shirreif 's use i 

 of the word mav as well be meant as that of 

 Vilmorin. 



However, before going deeper into such the- 

 oretical questions, we will first consider the 

 facts, as given by Shirretf himself. 



During the best part of his life, in fact during 

 the largest part of the first half of the nine- 

 teenth centurj^ Shirretf worked according to a 

 very simple principle. When quite young he 

 had noticed that sometimes single plants having 

 better qualities than the average were seen 

 in the fields. He saved the grains, or some- 

 times the whole heads of such plants separate- 

 ly, and tried to multiply them in such man- 

 ner as to avoid intermixtures. 



His first result was the '' Mungoswell's 

 wheat.'' In the spring of 1819 he observed 

 quite accidentally in a field of the farm of that 

 name, a single plant which attracted his atten- 

 tion by a deeper green and by being more heav- 

 ily headed out. Without going into further de- 

 tails, he at once chose this specimen as the start- 

 ing point -of a new race. He destroyed the sur- 

 rounding plants so as to give it more space, ap- 

 plied manure to its roots, and tended it with 

 special care. It yielded 63 heads and nearly 



