“ throughout the bay, but is confined to the space of a few rocks,
on which it forms, as it were, a colony, or is gregarious.” It
appears by no means indifferent to what plant it attaches its
fronds, being very generally found growing on Ftilota sericea,
though frequently also on Cladophora rupestris. I am not aware
that it ever infests any other Algse.
The nearest affinity is with E. hrachiatus (FI. IV.), from
which it is most readily known by the difference in the fruit, the
spores being in that species lodged in swellings or enlargements
of the smaller branches in the axils of the opposite ramuli; and
in this being formed by a metamorphosis of the ramuli themselves.
My friend. Professor Kiitzing, strongly urges that this
difference indicates, not a different species, but a different condition
of the same species ; in like manner as the two modes of
fructification found in the Eloridem are not to be regarded as
specific characters. There is something, certainly, still to be
cleared up respecting the fructification of the Ectocarpi, to reconcile
the varying appearances which the organs of reproduction
assume in different species. Nevertheless 1 am disposed to
retain the present species distinct from E. hrachiatus, at least,
until their identity be proved; because, independently of fructification,
there is a difference in aspect, more readily seen than
described in words, and because they are found as parasites upon
different Algae. Both species have been collected and observed
by very accurate botanists, who do not find them intermixed,
and are firmly persuaded that they are essentially different.
Dr. J. D. liooker brought from Cape Horn an Ectocarpus {E.
geminatus. Hook. fil. et liarv.) closely resembling oim E. sphcero-
phorus, and also forming spores by an alteration of the ramuli;
but its spores are of a conical, not spherical, form. It would be
very interesting should future observations detect this analogous
species on the shores of the Shetland Islands.
A
A
I'lg. 1 . E c t o c a e p u s s p h a j e o p h o e u s ; a t u f t 0/ ¿¿e natural size, growing on
a frag-meiit of Ftilota sericea. 2. Portion of a brancli. 3. Eamuli, with
spores;—b o t h ’