48 PLANT-BREEDING 



sketch has led us is obviously that by very different methods 

 and under the influence of widely divergent theoretical 

 premises, equally good improvements have been obtained. 

 We may add that even in the number of new and useful 

 varieties produced, no single one among these methods evi- 

 dently excels the others. It is always a small number, not 

 exceeding ten or perhaps twenty novelties in each single 

 instance, and ordinarily even far less. Thus all these princi- 

 ples are seen to have only a limited application, and perhaps 

 failures have been more numerous than successes although 

 as a rule only the latter have been recorded. Hence we may 

 conclude that our knowledge of the variability of cereals 

 is not yet sufficient to enable us to exhaust all of its possibili- 

 ties, or at least that such a knowledge was not in the posses- 

 sion of the breeders whose great achievements have given 

 the material for our present sketch. 



B. THE SWEDISH AGRICULTURAL EXPERIMENT STATION 

 AT SVALOF. 



During the last twenty years, experiments in the breed- 

 ing of cereals and other agricultural crops have been con- 

 ducted on an unusually large scale at the Swedish experiment 

 station of Svalb'f . Considered from a practical point of view, 

 they have produced quite an astonishing number of new 

 races, by which agriculture in almost all the districts of 

 Sweden has been greatly improved, and which are now at- 

 tracting the attention of numerous agriculturists in other 

 countries. Their methods took their origin from those fol- 

 lowed in Germany, but were soon changed, and may, at 

 present, be more closely compared with the work of Le Cou- 

 teur and Shirreff, though developed quite independently 

 of these men, whose ideas were, at that time, only locally 

 appreciated. 



For the students of the problems of evolution, the methods 



