Cereals. 1 07 



with a vast assemblage of varieties of unknown origin. 

 According to Nilsson,, every larger or smaller "species" 

 includes hundreds of such varieties. In the second place 

 one of the tasks of rational breeding is to cross these 

 sorts with one another as much as possible in order to 

 combine their characters in the particular way which 

 seems most desirable for each separate case. The origin 

 of these hybrids is in most cases unknown, or at best 

 the information concerning them is either incomplete or 

 uncertain. The excellence and variety of our cereals 

 can only be attributed in a small degree to the direct 

 effects o*f selection. 



In his excellent treatise Anlcitung ::nr Gctreidemich- 

 tung Von Rumker distinguishes between empirical and 

 methodical selection.^ Empirical selection is the general 

 process which every intelligent farmer ought to prac- 

 tise ; it is carried on on a large scale in certain districts, 

 as for example the Probstei, where the entire harvest is 

 sold as seed. Empirical selection consists at least in 

 choosing the best piece of the field, and in growing the 

 seed for the next year on it. Or the harvest is threshed, 

 the largest and heaviest grains are separated from tlie 

 less valuable ones by a hand sieve or by a centrifugal 

 machine, and kept for sowing. Thirdly a sorting by 

 ears is carried out at mowing time and consists in set- 

 ting aside the beast ears borne by the strongest halms in 

 sufficient quantity to provide for the elite race for the 

 ensuing year. 



The object of empirical selection is to keep the dif- 

 ferent kinds pure and to put a stop as much as possible 



*Dr. Kurt von Rumker, Anleitiing ziir Getrcidczi'ichtung auf 

 ivissenschaftlicher und praktisclicr Gnindlage, Berlin, 1889. Com- 

 pare also RisLER-RiMPAU, Der Weizenbau in the Thacr-Bibliothek, 

 1888. 



