of the filaments, I felt satisfied tha t its proper place was
Avith the Conjugateoe, and referred it to Mougeotia. This
reference did not, in all respects, seem satisfactory, for while
the true species of Mougeotia are almost constantly found
united, C. ericetorum is very rarely met Avith in tha t condition.
So rarely, indeed, as to make it apparent that the
species is reproduced independent of any union of the filaments.
The habit of C. ericetorum was so different from
that of the true Alougeotia, V&mg more tha t of a Scytonema,
th a t I had determined to place it in a genus by itself ; a step
which, on looking over Kiitzing’s “ Phycologia Generalis,”
I found to have been already taken. Kiitzing thus accurately
defines the genus : —
“ Trichomata simplicia vel subramosa, parenchymatica
hologonimica, primum viridis, delude purpurascens ; cellulæ
cartilagineæ, crispæ, interdum didymæ ; spermata nunc in
trabeculis, nunc lateralia, globosa.”
1. Z y g o g o n ium e e ic e t o k um Kutz.
Plate X L I . Figs. I, 2.
Char. Filaments not unfrequently branched. Cells usually
about tioice as long as broad, rarely uniting, but frequently
emitting elongated and irregular processes, which are usually
to be regarded as rudimentary ramuli. Fndochrome occasionally
becoming effused, generally from one cell into
an adjoining one in the same filament, but sometimes that
from both cells passes into a space formed between the two
utricles.
C. ericetorum Harv. in Hook. Brit. Flora, also in Manual,
p. 125. ; F . Bot. t. 1553. ; Grev. Crypt, t. 261. f. 1.
I t lias elsewhere been stated that I had been induced,
from the detection of ramuli on some of the filaments, to
consider Conferva ericetorum as referrihle to the branched
Confervoe. I t AVOuld appear, hoAvever, on closer examination,
tha t while it certainly, by the not unfrequent occurrence of
ramuli, exhibits a degree of relation to those species, yet that
its affinities with the conjugating tribe are sufficiently strong
to make it apparent that its proper station is with these, and
not with the branched species.
When a communication is about to he set up between two
cells in the same filament, the opposed extremities of those
cells are first seen to become slightly inflated, to point some-
Avhat and then hurst, effusing their contents sometimes into
a space which is formed gradually between the two cells,
but at others the endochrome of one cell passes directly
into the cavity of the other.
All the cells in a filament do not usually communicate
with each other at the same time, but at distant intervals;
and around those cells between which a communication is
about to become established, the investing membrane is observed
to he thickened considerably, pointing out to the
observer those cells which either have, or are about to take
on, the characters of reproduction.
A t one time I thought th a t the branches which I have so
often met with were spurious, and might have been formed
in the same manner as they sometimes are in M. genuflexa,
&c., viz. by the union of the extremities of certain filaments
at right angles with the cells of other filaments; but this
idea was dispelled by observing, that in the specimens in
which the branches occurred most abundantly, no union of
cells in the regular way was to be met with.
The colour no less than the condition of the endochrome
varies considerably in this species. In some specimens the
filaments are of a bright green, in Avhich case they have
always been found immersed in w a te r; Avhile in others, and
more frequently, they are p u rp le; of which colour they invariably
are when found spreading over swampy heaths.
Specimens of a beautiful green colour were recently sent me
by Mr. Jenner and Mr. Ralfs, and these, for some time,
puzzled me exceedingly.
I have no hesitation in referring to this species the C. p u r - '
purascens of Carmichael, and C. alpina Bory which is hut an
aquatic condition of the plant, and strongly suspect tha t Conf.
tortuosa Dillw. (the Zygnema littoreum Lyngb., and C. per-
reptans Carm.) might be referred to it likewise.
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