Oenothera Rubrinervis. 



329 



the appearance of a single new elementary character. 

 On the other hand it might be supposed that in mutation 

 the elements of the species are changed by groups. There 



Fig. 67. Oenothera rubrinervis. An entire flowering plant, 

 1900. Fourth generation of a rubrinervis-iamily which 

 arose in 1895 from seeds of O. Lamarckiana as shown in 

 the pedigree on page 262, that is to say from the second 

 generation of Lamarckiana in that culture. 



is abundant a priori and a posteriori evidence for the 

 view that the characters of plants are often associated 

 in groups in such a way that whole series of them react 



