THE MUTATIONS OF OENOTHERA STENOMERES lOI 
was normal and from which most of the seedlings were discarded. In 
the other cultures germination was poor, and all the plants were kept. 
It will be noticed that mutations were found only in the cultures 
characterized by poor germination. The writer usually sows the seeds 
from two or three capsules (400-900 seeds) in each germination pan. 
Unfortunately, the seeds were not counted for any sowings of Oe. steno- 
meres. In 1913, the first year in which plenty of garden space was 
available, all of the seedlings obtained were kept until maturity, and 
in that year the two mutations, mut. lasiopetala and mut. gigas, were 
discovered. In the following year several packets of old seeds, which 
has been left over from previous plantings, were sown, with the result 
that one lot of possibly a thousand old seeds gave only four plants, of 
which 3 were mut. lasiopetala and one was forma typica. The same 
seeds, two years before, had germinated normally and the young 
seedlings appeared uniform. Eight of them, carried to maturity, were 
all f . typica. It is clear that mut. lasiopetala is a mutation of infrequent 
occurrence, but that the seeds which give rise to it are for some reason 
longer-lived than those of f. typica. The phenomenon of selective 
mortality is probably very important in the operation of natural 
selection. In the article on Oe. pratincola mut. nummularia (1. c.) 
very clear evidence of differential fermination and selective mortality 
is presented. In the case of Oe. stenomeres mut. lasiopetala the latter 
phenomenon seems to account for the unexpected composition of small 
cultures. 
Oe. stenomeres mut. lasiopetala nom. nov.^ 
Before the rosettes of this mutation have attained a diameter of 
2 cm. they may be distinguished from the type form by their more 
densely pubescent, broader, sometimes almost orbicular leaves. The 
leaves of f. typica are ovate. Differences become more pronounced 
as the plants grow older. The mutation remains persistently in the 
rosette condition. The rosettes of the type, on the contrary, are 
transitory, for the species is an annual. The mature foliage of the 
^ The name of this mutation was originally published as Oe. stenopetala mut. 
lasiopetala (Amer. Journ. Bot. i: 237. 1914). The specific name Oe. stenopetala 
had been used in the writer's paper as originally submitted for publication, but was 
later altered to Oe. stenomeres on account of the prior publication of Oe. stenopetala 
Bicknell. In one place the preempted name escaped correction in the proof. The 
oversight is especially regretted because Mr. Bicknell's new species is likewise one 
of the cruciate Onagrae. It is not, however, at all closely allied to Oe. stenomeres, 
not has it yet been made the subject of experimental study. 
