NEW DIMORPHIC MUTANTS OF THE OENOTHERAS. 



97 



first group, but only one in the latter group, 

 results we get the following pedigree: 



1913 Mutant Mutant 



1914 First generation 



Combining these 



43 per cent Lactuca 



Lamarcklana 



I 



1915 Second generation 9 per cent Lactuca Lamarckiana Lamarcklana 



Although only two generations from the seeds of the original 

 mutant have been cultivated, it is evident that this new form 

 behaves exactly like the inconstant races of 0. scintillans, 0. cana, 

 and 0. pallescens. Under favorable conditions it splits into about 

 equal numbers of the mutant type and of the type of 0. Lamarcki- 

 ana. Moreover, a mutant dwarf has been produced. 



0. Lamarckiana mut. liquida (fig. 5, A).— In 1912 and 1913 

 a new type of mutant was discovered, which came next to 0. scin- 

 tillans, had flat and smooth leaves like that form, but the foliage 

 was much broader and lighter green. The individual mutants 

 resembled one another in all respects, save the size of the flowers ; 

 they were very slender and had leaves about two-thirds the size 

 of those of 0. Lamarckiana. The pollen was sometimes abundant, 

 but in other flowers rather scanty. 



All in all, I had 6 mutants of this type. One came from seed 

 of 0. Lamarckiana, but unfortunately it failed to produce good 

 seeds, although the fruits were well developed. Four others arose 

 from 0. lata x Lamarckiana, two in 1912, which also did not yield 

 fertile seeds, and two in 1913. The last one was found in the culture 

 of 0. pallescens mut. no. 1, and mentioned previously. The seeds 

 of the 3 fertile mutants were sown in 1914 and yielded small cul- 

 tures, which split up into two types, one repeating the mutant 

 parents in all respects, and the other differing in no visible way 

 from ordinary 0. Lamarckiana. Besides these there were some 

 mutants which happened to belong to allied types. Table VII 

 gives the size and constitution of these cultures. 



Table VII. 



Second generation of 0. liquida. 



