98 NEW DIMORPHIC MUTANTS OF THE OENOTHERAS. 



In each of these cultures 15 individuals have been allowed to 

 flower, about one-half of these being the liquida type and the other 

 half the Lamarckiana type. The 3 mutants were scintillans, pallescens, 

 and cana. All 3 have grown vigorously and flowered in August 

 and September; they differed in no respect from the races of the 

 same names. 



The percentage of typical individuals in the second generation 

 is about the same as for 0. cana (25 and 53 per cent), for 0. pal- 

 lescens (35 per cent) and for 0. Lactuca (43 per cent). From this 

 it may be concluded that the 4 races have the same hereditary 

 constitution which, moreover, is the same as in 0. scintillans. 



The next year (1915) I cultivated a third generation of the 

 second mutant of the table (mutant no. 1 from lata). The har- 

 vest had been small, as in the previous generation, and only 33 

 seeds germinated. Of these 9 were liquida, 1 was pallescens, 1 oblonga, 

 and the others Lamarckiana. All of them have flowered. The 

 percentage for liquida was 27, or about the same as in the first 

 generation. Moreover, I have sown for each of the 3 cultures of 

 1914 the seeds of one or two typical individuals, and also for each 

 of them the seeds of two of the atavistic or Lamarckiana type. 

 These 6 last sowings contained 150-300 seedlings each, together 

 1311, of which 8 were mutants (3 oblonga, 4 lata, 1 cana); the 

 remainder were all of the Lamarckiana type, no liquida occurring 

 among them. The seedlings of the 4 liquida specimens gave the 

 results indicated in table VIII. 



Table VIII. 



Third generation of O. mut. liquida. 



The countings were made in June and July in the boxes in which 

 the seeds had been sown ; the plants were all young rosettes with 

 leaves 15 cm. long in the Lamarckiana type, and 6-10 cm. long 

 in the liquida specimens. The differences were clear and sharp. 

 The table shows that the splitting was almost exactly the same in 

 the third as in the second generation. 



