238 EXPERIMENTAL EVOLUTION LECT. 



is yielded by experiments on the beetroot, performed 

 some years later by the same writer, with the view of 

 obtaining a variety of this plant containing more 

 sugar than is commonly the case. 1 It is worth 

 recording, as it shows that through selection it is 

 possible to influence physiological variability, and the 

 result has been to increase the proportion of sugar 

 from 10 on an average to 12, 14 and even 16 per cent. 

 M. de Vilmorin notices a fact which it is well to state 

 here, when he says that it is better to select seeds from 

 plants belonging to a group with high average than 

 from plants yielding high maxima but also low 

 minima. 



A large number of facts from observation confirm 

 these results of experiment. Our domesticated 

 animals, our cultivated plants have been made to yield 

 so many varieties simply through selection. While 

 cultivation or domestication increases the tendency 

 towards variation as we all know, selection of 

 variations has led us to produce quite a number of 

 varieties of which we make use in very different 

 manners, because different variations have in turn 

 been selected according to the particular wish of 

 the selectors, or to the peculiarly interesting nature 



1 Note sur un Projet if Experience ayant pour but tfaugmenter la 

 Richesse saccharine de la Betterave. Loc. cit. (1890), and Note sur la 

 Creation June nouvelle Race de Betterave a Sucre. Loc. cit. and Comptes 

 Rendus, Nov. 1856. 



