684 



MUTANT RACES DERIVED FROM OENOTHERA 



determined. The cultures showed exactly the same splitting as is 

 known for the old race of Oe. Lamarckiana mut. scintillans. The 

 main types were scintillans, Lamarckiana and oblonga. Moreover, 

 there were barren seeds which amounted to 34 percent in the first 

 culture, and a small number of mutants. 



The countings on the beds are given in table 1. No. 1 and No. 2 

 were derived from the cross with velutina, Nos. 3 to 5 from that with 

 tardescens. 



For my race of the same name the figures are, in the main, 70 

 percent Lamarckiana, 18 percent scintillans, 10.5 percent oblonga 

 and 1.5 percent mutants (de Vries 1924 c). The conformity is thus 

 seen to be as close as might be expected. The mutants were of the 

 ordinary types, namely, hamata on the first bed, one semigigas in 

 each of the last three beds and liquida, pulla and pallescens in cultures 

 No. 4 and No. 5. 



Oenothera semigigas Mut. cana. 



From the cross with velutina, already cited, we had eight specimens 

 of cana, all of them with 15 chromosomes and of a pure type. Six 

 plants produced a sufficient supply of seeds, but with only a small 

 geiminating power. All of the seeds were sown and all of the seedlings 

 planted out. Counted during the flowering period they gave the 

 results presented in table 2. 



Table 2. 

 Oenothera semigigas mut. cana. Second generation. 



For my race of cana the corresponding numbers were almost the 

 same, namely, 62 percent Lamarckiana, 33 percent cana and 5 percent 

 of mutants (de Vries 1916 a, pp. 254, 256). Of the mutants in the 

 cultures of 1924 a relatively large number were dwarfs, namely, 8 



