Mutations and Evolution. 
141 
obtained mut. lata from CE. biennis, also a red-nerved ( rubrinervis) 
type and a Icevifolia. Stomps (1912a), in the cross CE. biennis 
X CE. biennis leptomeres Barth ( leptomeres=CE . biennis cruciata 
de Vries) observed one dwarf mutant ( biennis nanella) and one 
semigigas (with 21 chromosomes). The biennis parent was 
descended from a rosette collected by Stomps on the sand dunes 
near Wykaan-Zee in 1905, which gave a uniform race. The biennis 
leptomeres was derived from a plant originally collected in 1900 by 
Ernst de Vries near Santpoort, Holland, and from which a constant 
strain was obtained. In 1903, one dwarf (CE. biennis leptomeres 
nanella) arose in about 600 of the tall cruciate variety. The 
original leptomeres plant, when found in 1900, was surrounded by 
a number of normal biennis, and evidently had arisen as a mutation. 
TABLE II. 
Parallel Mutations in GEnothera. 
Species 
lata 
gigas 
semigigas 
Dwarfs 
cruciata 
elliptica 
$ 
Virescence 
nanella 
semialta 
debilis 
CE. iamarckiana Ser. 
X 
X 
X 
X 
(xy 
X 
(X)’ 
X 
CE. biennis Linn, 
X 
X 
X 
X 
(X)' 
X 
CE. grandiflora Sol. 
X 
X 
X 
CE. stenomeres Bartl. 
X 
X 
CE. pratincola Bartl. 
X 
CE. Reynoldsii 
X? 
X 
X 
Bartl. 
CE. suaveolens Desf. 
X 
CE. multiflora 
Gates 2 
X 
CE. grandiflora x 1 
' 
biennis 3 > 
X 
X? 
X 
X? 
F 2 and F 8 ) 
The significance of the various species and varieties with 
cruciate flowers will be considered later. The first experiments 
with pure CE. biennis were undertaken by Stomps (1914). He 
collected a rosette of this species at Beverwyk, Holland, in 1905, 
from which he obtained a pure line. Among over 900 plants 
belonging to the third and fourth generations, Stomps found 6 
mutants, 1 nanella , 1 semigigas and 4 sulfurea. The last differs from 
1 When enclosed in parentheses, the form is a presumptive mutation, but 
has not actually been obtained in a pedigree culture. 
3 For a description of this “ species,” probably of hybrid origin, see 
Gates, 1914b. 
3 Davis, 1913, 
