On the Species of the Genus Primula in Essex. 205
approaching more nearly to one than to the other. I have
always observed these hybrid plants in recently-cut woods,
where, doubtless, they are produced by the agency of insects
which indifferently visit both forms on the removal of the
cover. The only doubt that remains is, whether they can be
a caulescent variety of the Primrose "stimulated" by the
cutting-down of the woods. I think not, because—(a) I never
observed that cutting down a wood "stimulated" Primroses
in this direction ; (b) if it did, the stimulus would have had
time to pass off in many woods where I have found them;
(c) Primroses never produce such plants away from P. elatior;
(d) the eye-spot and general appearance is not that of the pure
Primrose. I have never observed whether or not the anthers
produce abortive pollen. The umbel, as might be expected,
is a somewhat irregular one, the flowers not drooping; and
solitary flowers are not numerous among them. I am per-
fectly convinced in my own mind as to their hybrid origin,
and the only thing that surprises me is their abundance. In
Grim's Ditch Wood I estimated that they composed 15 or 20
per cent. of all the Primula plants in the open part. In the
Hyde Wood I particularly noticed that they were only to be
found in the few spots where P. elatior grew sparingly, and
on these spots the hybrids composed about 60 per cent. of all
the Primula plants, but this was only in very limited areas of
a few square yards each. From this it is evident that in
England the Oxlip and the Primrose in a wild state cross
very freely with one another when intermixed.63 With the
Cowslip, which abounds throughout the whole of the elatior
district, the case seems to be different. On two occasions
only have I found it hybridizing with the Oxlip, although, as
already stated, careful search was made in places where both
grow abundantly intermixed. The first time was in Madghob's
Wood, on April 23rd, 1883, when I found a cluster of five or
six plants growing near the edge of the grown-up part of the
53 I have supplied the Kew Herbarium with specimens of this hybrid
(P. vulgari-elatior, Gren., P. acauli-elatior, Muret.), and also with some
of the more striking varieties of P. elatior. To the Royal Gardens I have
sent roots of this hybrid and of that produced with the Cowslip (P. uni-
color, Lange, P. officinali-clatior, Muret, and (?) P. tommasinii, Gren.).