202 GENETICS IN RELATION TO AGRICULTURE 



selection of best plants in order to maintain the improvement already 

 gained. One of the earliest breeders 'to use this method was Andr6 

 LeVeque de Vilmorin, who began selecting carrots about 1830. Soon 

 thereafter selection of sugar beets for seed production was begun in 

 France and Germany, first according to form of the root alone, but later 

 according to specific gravity and actual analyses of sugar content. 

 Mass selection later became the principal method of improving small 

 grains in Germany, and it has been known as the German method of 

 "broad breeding." The earliest prominent breeder of small grains was 

 W. Rimpau, who began his work with rye in 1867 and developed the 

 famous Schlanstedt variety. Later he worked with wheat extensively, 

 first by mass selection and, more recently, by hybridization of varieties 

 and subspecies. Although there have been scores of successful breeders 

 of each of the important small grains in Germany, Rimpau was the 

 first to engage in this work on a large scale. 



Mass selection in maize was begun as early as 1825, when J. L. 

 Learning, of Ohio, began the selection of best ears from his field for seed 

 corn. By repeating this process he soon developed a superior strain 

 that came to be known as the Learning variety. The same simple 

 method was employed in originating Ried Yellow Dent (1847), Morley 

 Prolific (1876), and Boone County White (1885). The famous Illinois 

 corn-breeding experiments, which will be described in later chapters, 

 were begun in 1896 by Cyril G. Hopkins, then Professor of Agronomy 

 in the University of Illinois. Among the other investigators who have 

 participated in this undertaking are East, Shamel and L. H. Smith. 

 The general result of the project has been the most convincing proof of 

 the efficacy and practicability of mass selection in corn, not only for the 

 chemical and physical characters of the grains but for other characters 

 of the corn plant as well. 



The improvement of cotton by mass selection has doubtless been 

 practised for centuries. Authentic records of the earlier methods used 

 in foreign countries are scarce, but the characteristic variability in 

 length of fiber, combined with the very practical value of increasing the 

 average length, must have appealed to growers, at least in the more prog- 

 ressive cotton growing regions of the world. In the South Carolina islands 

 according to Webber the sea island types of cotton have been developed 

 by consistent mass selection for early maturity, increased length of lint, 

 and greater productiveness from a West Indian perennial type which 

 was originally unsuited to conditions under which its derivatives 

 are now grown so successfully. Mass selection in cotton has been 

 resorted to also in the campaign against various plant diseases, 

 particularly cotton wilt, and for early maturity to avoid the ravages of 

 the boll weevil. 



