Artificial and Natural Selection 809 



exact determination of three hundred thousand 

 polarization-values of beets within a few weeks. 

 Such figures give the richest material for statis- 

 tical studies, and at once indicate the best roots, 

 while they enable the breeder to change his 

 standard in accordance with the results at any 

 time. Furthermore they allow the mass of 

 the beets to be divided into groups of dif- 

 ferent quality, and to produce, besides the 

 seeds for the continuation of the race, a first- 

 class and second-class product and so on. In 

 the factory of Messrs. Kuhn & Co., at Naarden, 

 Holland, the grinding machine has been mark- 

 edly improved, so as to tear all cell-walls asun- 

 der, open all cells, and secure the whole of the 

 sap within less than a minute, and without heat- 

 ing. 



It would take too long to go into further de- 

 tails, or to describe the simultaneous changes 

 that have been applied to the culture of the 

 elite strains. The detailed features suffice 

 to show that the chief care of the breeder in this 

 case is a continuous amelioration of the method 

 of selecting. It is manifest that the progres- 

 sion of the race is in the main due to great tech- 

 nical improvements, and not solely to the repe- 

 tition of the selection. 



Similar facts may be seen on all the great 

 lines of industrial selection. An increasing ap- 



