MUTANTS AND HYBRIDS OF THE OENOTHERAS. 



place, some of the leaf-characters arelincapable 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 O. lamarck- 

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



50 



45 



4.0 



25 



10 



0-3 



3-6 6-9 9r-I2 13-15 15-18 18-21 21-24 24-27 27-30 30- 



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

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

 meters; o-, 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; o-, 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. 



