packed filaments, a roundish mass of minute spores spread upon a hemispherical
central placenta. The tetraspores are scattered over the whole
surface of the plant wliich produces them, and are mostly triangularly
divided. Colour a dull purple, becoming greenish on exposure.
I am indebted to M. Lenormand for having pointed out to
me the identity between the Bhodomenia polycarpa of Greville,
and the older Fucus multipartitus of Clemente, which Greville
includes in his genus Chondrus; and also for a suite of beautifully
preserved specimens, showing the changes which this most
variable plant assumes, according to the circumstances under
which it grows; and I have had the additional advantage of
consulting, in the Herbarium of Mrs. Griffiths, an authentic specimen
of Fucus multipartitus, from Cadiz, which is in all respects
similar to some of our British individuals. Prof. J. Agardh,
while he transfers the Bhod. polycarpa and Chondrus multipartitus
of Greville to the reformed genus Gracilaria, retains both species.
With respect to the Fucus mruginosus of Turner, which I had
been in the habit of regarding as the typical state of G. multi-
partita, and which I had hitherto looked upon as truly distinct
from our British B. polycarpa-. a more careful examination and a
comparison of multitudes of specimens from very distant parts of
the world, induce me now to regard this as merely a variety originating
probably from the plant’s growing in rougher water, beyond
the influence of the estuaries; and consequently acquiring a firmer
texture, and narrower segments : the marginal processes are common
to all the varieties. A still more remarkable form of this
species is Agardh’s var. S. anyustissimus, of which specimens have
been kindly sent to me by Prof. J. W. Bailey, of New York, who
obtained them at Providence, Rhode Island, where vast quantities
of this variety grow on sandy bottoms. These specimens
are quite as slender as Gracilaria confervoides, and nearly cylindrical,
excessively divided, and forming bushy tufts. But that
the very narrow ones are mixed with others, which show a
decided return to the common form of the species, one would
never suspect them to belong to i t ; yet some are covered with
the characteristically abundant tubercles. Mr. Hore has found
at Plymouth, as Mrs. Griffiths informs me, specimens almost
equally narrow.
Fig. 1. G r a c il a r ia m u l t ip a r t it a -.— natural size. 2. A portion, showing the
pitted appearance of the surface :— slightly magnfied. 3. Section of frond
and tubercle, to show the structure of both. 4. Spores from the tubercle.
5. Tetraspores. 6. Section of a thicker portion of the fro n d :— all highly
magnifed.