346 



DARWINISM TO-DAY. 



arisen the three groups or families of elementary species that 

 de Vries has studied. In his garden other new forms also 

 arose from those that had been brought under cultivation. 

 The largest group and the most important one is that from 

 the original 0. lamarckiana form. The accompanying table 



CENOTHERA LAMARCKIANA. 



ELEMENTARY SPECIES. 



shows the mutations that arose between 1887 and 1899 from 

 these plants. The seeds were selected in each case from 

 self-fertilised plants of the lamarckiana form, so that the 

 new plants appearing in each horizontal line are the 

 descendants in each generation of lamarckiana parents. It 

 will be observed that the species, O. oblongata, appeared 

 again and again in considerable numbers, and the same is 



