108 Elementary Species 



the use of the word " selection." This word 

 was used by Sheriff as seen in the quotation 

 given, and it was obviously designed to convey 

 the same idea as the word * * lecta ' ' in the quo- 

 tation from Vergil. It was a choice of the best 

 plants from among known mixed fields, but the 

 chosen individuals were considered to be repre- 

 sentatives of pure and constant races, which 

 could only be isolated, but not ameliorated. 

 Selection therefore, in the primitive sense of 

 the word, is the choice of elementary species 

 and varieties, with no other purpose than that 

 of keeping them as pure as possible from the 

 admixture of minor sorts. The Romans at- 

 tained this end only imperfectly, simply be- 

 cause the laws governing the struggle for life 

 and the competition of numerous sorts in the 

 fields were unsuspected by them. 



Le Couteur and Sheriff succeeded in the solu- 

 tion of the problem, because they had discovered 

 the importance of isolation. The combination 

 of a careful choice with subsequent isolation 

 was all they knew about it, and it was one of 

 the great achievements to which modern agri- 

 culture owes much of its success. 



The other great principle was that of Vil- 

 morin. It was the improvement within the 

 race, or the " amelioration of the race " as it 

 was termed by him. It was introduced into 



