286 PLANT-BREEDING 



at least as rich in elementary species as the cereals. These 

 minor types can be distinguished by botanical marks which 

 are correlated to the time of ripening and to their yielding 

 qualities. Especially variable are the common Avena ela- 

 tior and the different species of Agrostis. The first of them 

 gave 14 distinct forms in the first trial, and later tliis number 

 was increased to about 50. 



In concluding this hasty survey of the results of the 

 methodical study of correlations at Svalof, I might emphasize 

 the great principle of the combination of the scientific and 

 the practical sides of the question. Selection on the ground 

 of practically valuable quaHties only, has been the rule until 

 very recently. Of course it was a good and reliable method, 

 but it was extremely limited in its application; on the other 

 hand, the whole history of the breeding process in Germany 

 consists of isolated cases. No doubt these have yielded 

 very valuable results, but the Svalof principle gets rid of 

 the incumbrances to a more universal use. By it the 

 breeder is enabled to single out hundreds of valuable strains, 

 and to select among them the very best. The search in the 

 field is made on the basis of marks which can be recognized 

 instantly by the experienced eye, upon a simple inspection of 

 the ears and panicles, of the stems and their branching, and 

 of the shape and size of the leaves. Thus the purely mor- 

 phological distinctions take the place of the agricultural 

 tests, which embrace measurements and estimates, that can 

 hardly be made for single individuals and never can be ap- 

 plied to so large numbers of specimens as can be compared 

 by purely scientific marks. A broad scientific foundation is 

 thus seen to be the means of abridging the practical work 

 and this to such a degree that the selection may be extended 

 and appHed to almost all the requirements of practice at 

 large. 



Two essential features of the selection work at . Svalof 



