On the Species of the Genus Primula in Essex. 169
plants are generally 1. leads one to the belief that they and
their seeds have a greater constitutional vigour than the s.,
which are thus easily eliminated in the "struggle for
existence." It seems as if the s. plants produced seed in
greater quantity, while the 1. plants prefer a better quality.
If only Mr. Darwin were yet alive we might have had one of
his keen speculations on this interesting subject. Speculation
alone, however, could never decide the question. Nothing
but observation and experiment can do so.25*
I have promised to recur to those Primulas in which the
1. plants produced the most seed. Mr. Darwin showed26 that
with nearly all Primulas the 1. flowers are considerably the
most fertile when illegitimately fertilized; when he protected
the flowers of primroses from insects the 1. were considerably
the most fertile, though this did not apply to the Cowslip.
It seems then as if the 1. plants when wider difficulties have
an advantage over the s. plants by reason of the better quality
of their seed-producing powers. Hence, perhaps, it may be
that in some of the plants whose seed I counted, and which
it is certain had never been properly fertilized, the 1. produced
most seed, contrary to what would have been the case under
favourable circumstances.
V.—Distribution of the Various Species of Primula in
Essex.
Primrose.—The following localities are given in the 'Flora
of Essex'27:—
"(1) Chesterford, Quendon, &c, but not common around
Walden; Dunmow, plentiful; (2) Halstead, abundant; Pan-
field; (3) between Dunmow and Chelmsford; (4) Stratford,
Woodford, common; Epping; (5) Warley and Brentwood,
frequent ; (6) Rochford and Maldon District, Southend;
(7) Kelvedon; (8) Dedham, Harwich. β. caulescens, Curt.
Lond., 4, 9; (1) Quendon Wood; (2) Roxwell. This is
often mistaken for P. elatior."
25* [See footnote on this subject in § VII. under P. elatior.—Ed.]
26 'Forms of Flowers,' p. 48.
27 'The Flora of Essex.' By Ch S. Gibson, F.L.S.; London, 1862,
p. 247.
N