MUTANTS AND HYBRIDS OF THE OENOTHERAS. 



the types embraced by the hybrid. In this scheme it was found most 

 convenient to apply the terminology generally used to designate the 

 aspect of an individual to that of the separate characters, and qualities 

 which were fully dominant and accurate representations of the paren- 

 tal forms were placed under the heading of ' ' unilateral ; ' ' those which 

 approximated the type of one parent closely, but did not represent it 

 sufficiently to be identical with it in ordinary descriptive work, were 

 classed as ' ' goneoclinic " to that type, while those in which an average 

 of the paired characters was apparent were placed under ' ' interme- 

 diate." It is evident that the "intermediate" of Correns would 

 embrace both the " intermediate " of the above classification and the 

 goneoclinic departure from it on either hand. Goneoclinism may well 

 be the extreme of fluctuating variability instead of a modification of 

 a group-quality. The scheme used below has been found most con- 

 venient for this special discussion, but it is not urged as the best 

 method for the general estimation of hybrids. 



Tabulated analysis of the characters occurring in the various types of the hybrid 

 Onagra lamarckiana X Onagra biennis. 



No. 2.1. 



The notable feature of the structure of this type consists of the forms of 

 leaves exhibited by the stem. The rosettes and leaves of the stem which are 

 attacked by the fungus are almost exact counterparts of those of O. biennis, 

 while the upper portions of the shoot bear foliage-organs, very similar to those 

 of O. lamarckiana. The tendency to being attacked by the fungus seemed con- 

 fined wholly to this type, which is entirely unlike the remainder of the progeny in 

 characters not affected by the parasite. 



