OENOTHERA MUTANTS WITH DIMINUTIVE CHROMOSOMES 505 
which are of particular interest, those which have appeared but once 
or twice or which have appeared more frequently, but in every case 
have failed to come to flower, will be designated temporarily by type 
numbers only. 
It may be understood that all facts and theories embodied in the 
reports of this series pertain only to the plants of the Lamarckiana 
group, unless otherwise stated. 
As a preliminary to the study of 14 + -chromosome forms, we may 
briefly consider the 14-chromosome mutants which have appeared 
in the Cold Spring Harbor cultures. 
B. 14-CHROMOSOME Mutants 
Five hitherto undescribed types, whose chromosome numbers 
have not been previously announced, appeared in cultures of 0. 
Lamarckiana, 0. lata, 0. nane'la, etc. All were found to have 14 
chromosomes. 
(i) Type 2787 and (2) type 2803 are unimportant forms and may 
be passed by for the present. . .. 
(3) Type 3539V found in a 1908 culture of 0. Lamarckiana, had 
narrow, asymmetrical leaves, a character which persisted throughout 
life. The majority of the flowers had 4+-i'ayed stigmas. The 
somatic chromo&ome number of this plant was ascertained in 1909. 
(/\.) O. plicatula appeared among the offspring of a selfed lata 
mutant in 1909. It was very beautiful and thrifty in appearance. 
Coming to flower as an annual, it attained a height of about 9 dm. when 
full grown. As in the case of 0. Lamarckiana and other forms, a circlet 
of rosette branches was given off (text fig. i), those of the mutant 
ascending more rapidly than the rosette branches of 0. Lamarckiana. 
The buds were quadrangular, the sepals attaining the deep red of 
rubrinervis. The open flowers measured about 7-8 cm. in diameter, as 
a rule, and readily attracted the eye hy the peculiar markings shown in 
the accompanying photographs (text figs, i and 2 ; compare the latter 
with a flower from O. Lamarckiana, text fig. 3) . These troughs or ridges, 
as they may be called, according to the surface of the petal from which 
they are viewed, result from a somewhat too snug fit of the quadran- 
gular cone of petals within the quadrangular cone of sepals. Since the 
distance between the angles of neighboring sepals appears to be less, 
in such instances, than the distance between the angles of the petal 
