MUTANTS AND HYBRIDS OF THE OENOTHERAS. 41 



place, some of the leaf-characters are]incapable"of quantitative expres- 

 sion, such as the degree of crinkling of the leaf, which is a striking, 

 though not an absolutely distinctive feature of the leaf of 0. lamarck- 

 iana. Some leaves of O. rtibrinervis are also crinkled, but it is a gen- 



70 



66 



m 



m 



60 



45 



40 



35 



:;o 



35 



20 



15 



10 



Fig. 5. Variation in total branch-length of Onagra lamarckiana and O. 

 rubrinervis. O. lamarckiana: Range, 3.65 to 8.48 meters; M., 6.68 + 0.20 

 meters; <r, 1.85 ± 0.14 meters; C. V., 20.2 ± 2.2 per cent. O. rubrinervis: 

 Range, 7.79 to 29.98 meters; M., 18.19 ± 1.30 meters; a, 7.95 ±0.92 meters; 

 C. V., 43.7 ±5.1 per cent. 



eral character of the leaf of 0. lamarckiana and only occasional in 

 0. rubrinervis. Other characters, although measurable, present tech- 

 nical difficulties incommensurate with the value of the results, as, for 

 instance, leaf-thickness and degree of pubescence. The leaf of 0. 



