FIFTEEN- AND SIXTEEN-CHROMOSOME OENOTHERA MUTANTS 85 
were planted at spaced intervals in pans of sterilized soil, December 
II of the same year. 129 germinations resulted; 2 plants died uniden- 
tified as seedlings and a third, identified as 0. Lamarckiana, died later. 
The remaining 126 were transferred to the garden May 12, 1909. 
One lata from each of the three 1909 cultures was then selfed and the 
259 seeds obtained were sown in the same manner as those of the pre- 
ceding season, March 7, 1910. 99 germinations resulted; all of the 
seedlings survived and all of the young plants were transferred to the 
experimental garden May 16, following. 
Of these 226 plants, 109 (approximately 50 percent) were clearly 
identified as 0. lata, 8 as O. lata (?), 57 as 0. Lamarckiana (approxi- 
mately 25 percent) and 4 as 0. Lamarckiana (?). The chromosome 
numbers of the plants in the second and fourth groups are unknown. 
In addition to the foregoing there were 7 distinct types of 15-chromo- 
some mutants (23 individuals) which could not be classified either as 
0. lata or as /a/a-like forms. Still other mutant types, whose chro- 
mosome numbers were unknown, were believed to be 15-chromosome 
forms. In addition to the 57 Lamarckianas there were 3 types (4 
individuals) of 14-chromosome mutants, quite unlike 0. Lamarckiana. 
These are believed to represent approximately the total number of 
14-chromosome forms produced. 196 of the 226 plants grown rep- 
resented types whose chromosome numbers are now known, and but 
one of the 196 had 16 chromosomes. De Vries's mutants were not 
classified, but it is quite clear that no one of the 94 offspring which 
MacDougal obtained from selfed lata had 16 chromosomes. We do 
not know how many of MacDougal's and de Vries's seeds failed to 
germinate, but we have seen that 63 percent of the Cold Spring Harbor 
seeds sown failed to germinate in the few months allowed them, hence 
we do not know what would have been the relative percentages of 
1 4-, 15- and i6-chromosome forms, had all the viable seeds sown 
germinated. 
In connection with these studies of selfed latas, the results obtained 
from crosvsing one of these 1908 mutants with 0. Lamarckiana will be 
of interest. In 1908 I pollinated 0. lata, mutant No. 3500, with 
0. Lamarckiana, No. 3814, and covered the stigmas of the latter plant 
25 In addition to the 14-, 15- and i6-chromosome offspring referred to, one 21- 
and one 22-chromosome mutant were produced, as previously reported (Lutz, '12). 
The 226 offspring of these six selfed latas will be carefully tabulated and fully de- 
scribed in a later report . 
