volume.

Besides the genera Primula and Hottonia, Androsace (vel Gregoria, vel Aretia)
vitalliana is heterostyled. Mr. Scott fertilised with their own pollen 21
flowers on three short-styled plants in the Edinburgh Botanic Gardens, and not
one yielded a single seed; but eight of them which were fertilised with pollen
from one of the other plants of the same form, set two empty capsules. (1/19.
See also Treviranus in 'Botanische Zeitung' 1863 page 6 on this plant being
dimorphic.) He was able to examine only dried specimens of the long-styled
forms. But the evidence seems sufficient to leave hardly a doubt that Androsace
is heterostyled. Fritz Muller sent me from South Brazil dried flowers of a
Statice which he believed to be heterostyled. In the one form the pistil was
considerably longer and the stamens slightly shorter than the corresponding
organs in the other form. But as in the shorter-styled form the stigmas reached
up to the anthers of the same flower, and as I could not detect in the dried
specimens of the two forms any difference in their stigmas, or in the size of
their pollen-grains, I dare not rank this plant as heterostyled. From statements
made by Vaucher I was led to think that Soldanella alpina was heterostyled, but
it is impossible that Kerner, who has closely studied this plant, could have
overlooked the fact. So again from other statements it appeared probable that
Pyrola might be heterostyled, but H. Muller examined for me two species in North
Germany, and found this not to be the case.


CHAPTER II.

HYBRID PRIMULAS.

The oxlip a hybrid naturally produced between Primula veris and vulgaris.
The differences in structure and function between the two parent-species.