Mutants and hybrids of the oenotheras . relation between the length and breadth of the leaves of 0. rubri-nervis than in 0. lamarckiana. Correlation tables of these two charac- MUTANTS AND HYBRIDS OF THE OENOTHERAS. 47 ters are shown in figs. 12 and 13. The lesser correlation of the for-mer isapparent to the eye in the more scattered distribution of thevariates. The coefficients of correlation are as follows : Onagra la-marckiana, ± ; Onagra rubrinervis, ± is simply another way of expressing the fact that the leaf-form ofO. rubrinervis is more variable than that
Mutants and hybrids of the oenotheras . relation between the length and breadth of the leaves of 0. rubri-nervis than in 0. lamarckiana. Correlation tables of these two charac- MUTANTS AND HYBRIDS OF THE OENOTHERAS. 47 ters are shown in figs. 12 and 13. The lesser correlation of the for-mer isapparent to the eye in the more scattered distribution of thevariates. The coefficients of correlation are as follows : Onagra la-marckiana, ± ; Onagra rubrinervis, ± is simply another way of expressing the fact that the leaf-form ofO. rubrinervis is more variable than that of its parent-species. If increased variability and decreased correlation be, as here indi-cated, a general feature of those characters in which a mutant departsmarkedly from the parental condition, how is it to be interpreted? Itis hinted by Weldon (02) that these mutants are possibly the result ofselection and isolation. No one can deny that there has been selec-tion and isolation in their culture, but it may be questioned whether. 35-26 27-28 29-30 31-32 33-34 35-36 37-38 3J—10 11-42 Fig. 10. Variation in the mean width of leaves of Onagra rubrinervis and Curve for O. rubrinervis shaded with lines risingto the right. Kange:O. rubrinervis, to mm.; O. lamarckiana, to mm. these processes have been carried on to such an extent as to explainthe peculiar behavior of the mutants as compared with that of anextreme variate. This question will not be satisfactorily answereduntil a newly arisen mutant shall be subjected to various conditionsof cross and self fertilization, and the results are studied seems fair to assume that there has been a more discriminatingselection in the case of the several mutants than in O. lamarckiana. Itis therefore something of a surprise, if Weldons suggestion be true,to find the latter less variable in nearly every character studied. Thissurprise is due to what may be a false assumption, namely,
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