262 



BOTAXICAL GAZETTE 



color as in the parent form, but much more crinkled and uneven, 

 not as gray as in 0. ca>ia, nor as hairy as in this form. 



The impossibiht>- of distinguishing the young plants before 

 planting out evidently makes this mutant less fit for the determi- 

 nation of splitting percent- 

 ages, because the sorting 

 and counting has to be 

 done on the beds. In my 

 experiments I have ahvaj's 

 counted the indix-iduals of 

 the two types at the begin- 

 ning of the flowering 

 period, since at this time 

 the Kmits between the two 

 groups are the most sharp. 

 Moreover, this simi- 

 larity between the mutant 

 and the parent species 

 must diminish the chances 

 of discovering mutant 

 specimens of the new t^'pe. 

 This is probably the reason 

 why it was not observed 

 before 191 1. Since that 

 year new mutants of the 

 palksccns t}'pe have more 

 than once arisen from 0. 

 Lamarckiaua and from 

 some of its derivatives, 

 especially in 19 14. All of these mutants exacth' resembled the 

 first one in their whole structure and in all their marks. 



I have made pedigree cultures of the offspring of my first three 

 mutants. These arose from seed of the same parent plant of 

 1909, which belonged to the second generation of a guarded strain 

 of 0. Lamarckiana, derived from a rosette collected in 1905 in the 

 original field near Hilversum. One part of this seed was sown in 

 1910 and yielded, among about 500 specimens, i pallescens, together 

 \\-ith I rubriiiervis, 3 oblonga, 2 lata, 1 scintillans, 1 nanella, the 



Fig. 4. — Oenolhcra Lamarckiana mut. pal- 

 esccns: 3 typical leaves of the rosette of radical 

 June 16, 1914. 



leaves ; 



