382 BOTANICAL GAZETTE {MAY 
The percentages in April, as well as those found in August, show 
that the coefficient of mutation for ochracea is wholly different from 
that for Jorea and from the ordinary coefficients for the mutability 
of O. Lamarckiana, O. biennis, and other species. The average of 
the three figures for ochracea given in table I is 26 per cent, and this 
figure is somewhat too low on account of the losses mentioned. It 
is evident, however, that it differs from normal coefficients of 
mutability in the same way as the mass mutations of BARTLETT, 
and that the production of mut. ochracea from O. grandiflora must 
be considered as another instance of this phenomenon. Here the 
mass mutation is repeated in the succeeding generations of the pure 
line, and, in addition, mutations into lorea and gigas occur in the 
usual way. 
O. grandiflora mut. ochracea.—This species is well known as 
more strictly annual than any other of the same group. In spring 
it hardly makes any rosettes of radical leaves, but at once produces 
its stem. So did all my mutants, but especially the ochracea begins 
to make its stem when still very young and before being planted out. 
Its foliage is yellowish green, running parallel in this respect to 
O. suaveolens mut. lutescens (7). Even as in this last one, the leaves 
are strikingly broader and somewhat shorter than in the parent 
species. This insufficiency of the green color causes the young 
plants to stay behind the normal ones in their development, and by 
June they are much weaker. Afterward the new leaves assume 
a darker green, and in the fall the difference is often very small. 
The weakness remains, however, and the stature is low during the 
flowering period, reaching only 50 cm. in the beginning of July, — 
the normal plants are 70-80 cm. in height. 
Most of the chlorophyll is developed along the veins. The teeth 
along the margin usually have red tips. The branches stand out 
from the stem at wide angles, sometimes almost horizontally. The 
spikes are loose, but the flowers are large and provided with a rich 
supply of good pollen; the fruits are cylindrical and often thin. 
These differences are small, apart from the color, but they are very 
constant. In fig. 1 they do not show so strikingly as they do on 
the beds. In consequence of the pale green color of the leaves the 
stems are thin and their wood is insufficiently developed; they are 
