younger parts of the stem iu old plants, are flat and leaf-like, bi-pinnate ;
the pinnules furnished with a midrib, and muciferous pores, with a crenate
or subdentate margin, and varying from a line to two or three lines in breadth.
Receptacles one or two lines long, simple or forked, smooth, snbtorulose,
lanceolate, terminating most of the upper pinnæ of fertile specimens, and
frequently subtended by vesicles. Colour dark in the stem ; a pale olive in
the branches. Substance between coriaceous and cartilaginous, brittle when
dry.
I follow Turner, and all succeeding Britisli writers, in uniting,
under the common name foeniculacea, the Fucus discors and F.
abrotanifolius of Linnæus, which continental authorities, without
exception, retain in the rank of species. So far as a judgment
may be correctly formed from dried specimens, I fully agree with
Mr. Turner, that “ each shape passes into the other by gradations
so imperceptible that no line can be drawn between them and
this excellent author further remarks, that in separating it into
distinct varieties, he has rather yielded to the feeling of weakness
than followed the dictates of his judgment ; fearing that if he
did otherwise, he might be accused of presumption, or even of
a worse motive, in refusing to find characters sufficient even for
varieties, where other botanists have had no hesitation in laying
down such as constitute species. I have not myself had much
opportunity of examining the living plant, but I place implicit
reliance on the accruacy of the observations made during many
years familiarity with this species, by my often mentioned friend
Mrs. Griffiths, who states that such specimens as grow in deep
water, where they are seldom or never exposed by the tides,
constitute the F. discors of authors, especially if collected in
summer, at which season they are extremely luxuriant, with
broad leaves and large air-bladders ; and that fronds which are
developed in shallow tide-pools, or collected late in autumn or
winter, being more branched, and having narrower leaves, make
the F. abrotanifolius. On the depth of water, or ditference of
season, therefore, depend all the characters on which it has been
attempted to erect two species.
CysTosEiBA ECENICCLACBA:— of the natural size. 3. Portion of a leafy brancblet.
3. Air-vessels and reeeptacles. 4. Transverse section of a receptacle:—
more or less magnified.