The
mean diameter of these two lots of twenty grains was to that of twelve grains
from another short-styled flower as 100 to 75: here, then, the grains from the
short-styled form were considerably smaller than those from the long-styled,
which is the reverse of what occurred in the former instance, and of what is the
general rule with heterostyled plants. The whole case is perplexing in the
highest degree, and will not be understood until experiments are tried on living
plants. The greater length, and more papillose condition of the stigma in the
short-styled than in the long-styled flowers, looks as if the plant was
heterostyled; for we know that with some species--for instance, Leucosmia and
certain Rubiaceae--the stigma is longer and more papillose in the short-styled
form, though the reverse of this holds good in Gilia, a member of the same
family with Phlox. The similar position of the anthers in the two forms is
somewhat opposed to the present species being heterostyled; as is the great
difference in the length of the pistil in several short-styled flowers. But the
extraordinary variability in diameter of the pollen-grains, and the fact that in
one set of flowers the grains from the long-styled flowers were larger than
those from the short-styled, is strongly opposed to the belief that Phlox
subulata is heterostyled.
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