Sugar Beets. 99 



maize and other cereals to northern locaHties and to 

 mountain districts, in other words to the extension of 

 the cuhure of cereals into higher altitudes and latitudes. 

 This end is usually attained by shortening the period of 

 growth and by being content with a correspondingly 

 smaller harvest. In the case of chicken-maize, for ex- 

 ample, the duration of life was shortened from four to 

 three months in the course of five years. The same 

 happened in the case of rye and wheat. During the first 

 few years of the culture it is only the individuals that 

 flower first that ripen their seeds, and this of itself brings 

 about an effective process of selection. In the same way, 

 though in this case deliberately, the flowering time of 

 Chrysanthemum indicnm has been partly shifted back 

 to July and partly advanced into the following February. 

 The same is true of innumerable garden plants, of various 

 varieties of cucumbers, and so on. 



But the available experience on acclimatization does 

 not go much further than this;^ and we ma}^ be quite 

 sure that new specific characters have never arisen in this 

 way. 



§ II. SUGAR BEETS. 



Sugar beets afford the finest example of the process 

 of artificial selection. In no other plant under culti- 

 vation has the technique of selection reached so high a 

 pitch of perfection ; in no other is the method so sure 

 or the result so certain. There is now no sale for beet 

 seed which has not been the result of careful selection. 



Experiments in the selection of sugar capacity began 

 about 1850. This instance shows best, therefore, what 



^ A review of the subject is given in J. Costantin's splendid 

 work: Accomodation dcs planfcs aux climats froid ct chaud. Bull. 

 Scientif. de Giard^ XXXI, 1897, p. 489. 



