On the Species of the Genus Primula in Essex. 183
as the plant grows in a favourable or an unfavourable situa-
tion. Its variations (with the trifling exceptions just referred
to) may nearly all be set down as monstrosities, due, in all
probability, to stimulation, as they occur but rarely when the
plant grows under cover.
Fig. 3.—Abnormally large umbel of P. elatior, with flattened (fasciated)
scape or "stalk."
One of the earliest results of stimulation consists in an
increase in the size of the plant, which often produces ten or
twelve umbels with thick round stalks, a foot high (sometimes
more), the umbels consisting of ten, twelve, or fifteen un-
usually large and healthy-looking flowers. This is what
happens to most plants; of course there are smaller ones,
but some umbels are produced which are still more abnormal,
and in woods recently cut down these are by no means un-
common. Their stalks generally begin to thicken more or
less sideways, until they are often a quarter of an inch,
or even sometimes half an inch, broad, but no thicker
than usual. Often, too, they are over a foot long. But