io6 
H. H. BARTLETT 
to narrow-leaved derivatives which otherwise have the giga^-character- 
istics. 
From the very first the young rosettes of mut. gigas are larger and 
stronger than those of typical Oe. stenomeres. The leaves are half 
again as broad and much more densely pubescent. In nature the 
mutation would doubtless be a biennial, for the rosettes persist through 
early summer and have a tendency not to flow^er until late fall. It has 
already been remarked that f. typica is an annual. Among many 
hundred F5 plants in the garden of 1914 it was difficult to find one from 
w^hich rosette leaves comparable with those of the mutation could be 
obtained for the comparison shown in figure 2. 
From figure 2 it will be seen that the contrast in leaf-breadth 
betw^een parent and mutation is very great. Whereas the length of 
the longest leaves of either is about 300 mm., the breadth is about 40-45 
mm. in f. typica and 70-75 mm. in mut. gigas. The same relative 
leaf-breadth obtains in the stem leaves, of which a typical series from 
each form is shown in figure 3. The buds of the mutation are a third 
again as long as those of f. typica, and more than proportionately thick 
(v. fig. 4). In extreme cases the buds, including the ovary, are 90 
mm. long. The pollen giains have four germination points instead of 
three, and are therefore quadrangular instead of triangular. They are 
larger than the triangular grains of the type. A very few of them are 
triangular, as in the type, and a considerably larger number have five 
points. The pollen character was verified in the original mutation 
and in every plant of the Fi progeny which bloomed. Gates has shown 
that the same pollen difi'erences exist in the case of Oe. Lamar ckiana 
and Oe. gigas. 
The original plant of mut. gigas bloomed late in the summer, and 
few seeds w^ere obtained. The Fi progeny which they produced may 
be summarized as follows: 
Seeds Plants 
Capsule A 91 46 
Capsule B 69 25 
3 small capsules 85 31 
Total Fi 245 102 
Of the 102 plants only 63 reached maturity. The rest died or 
failed to flower. These 63 plants included 54 of typical broad-leaved 
mut. gigas, 6 narrow-leaved variations otherwise similar to mut. gigas, 
and 3 secondary mutations. Of the secondary mutations two were 
