On the Species of the Genus Primula in Essex. 151
I shall also introduce observations corroborative of the
facts brought forward, made on various other species of
Primula; but the foregoing are, so far as I am aware, the
only forms inhabiting the County of Essex.
I have to express my thanks to the late Mr. G. S. Gibson,
to Prof. Boulger, Mr. J. G. Baker, Rev. W. W. Newbould,
Mr. Rosling, Mr. William Cole, and other friends, for assist-
ance which they have kindly rendered to me in various ways.
II.—The Phenomena of "Heterostylism" in the Genus
Primula.
All botanists are aware that our British species of Primula,
and indeed most members of the genus, bear dimorphic
heterostyled flowers; but as a good deal that I shall here-
after say will be upon this subject of heterostylism, and as
Fig. 1.—Vertical sections of, a, long-styled, and b, short-styled Primrose.
[From Dr. Hooker's 'Primer of Botany,' by kind permission of Messrs.
Macmillan & Co.]
some who read these remarks may desire to have more fully
before them a description of this interesting peculiarity, I
have thought it best to append a brief summary of what is
known concerning its nature and effects.
In most species of Primula there are two forms of flowers
differing principally in the length of the style, or, to speak more
correctly, in the relative position of the anthers and the
stigma. This is the most obvious difference, but there are
others of but little less importance. In the long-styled or
"Pin-eyed" form (fig. 1 a), the style is sufficiently long to
support the stigma at the top of, or entrance to, the tube of
the corolla. The stigma is globular and very rough, being