inflated cells occupied with sporangia or globidcs, is q>iitb
consistent with the idea of these bodies being formed by the
contents of tAVO cells, since each may be in contact ou cither
side AA’ith an inflated cell. In the very rare instances in Avhich
three or four contiguous cells occur, I have never noticed
a perfect globule in each of these, and even if such ever exist,
each globide yet might he formed not indeed of the entire
contents of tAVO cells, but still of a portion of the green matter
of tAVO.
]\I. Leon Ic Clerk thus defines the genus Proliféra.
“ Filamentis loculatis simplicibus, matcriii viridi granulis
fulgidis aspersa totaliter rcplctis. Singulo loculo, fructifica-
tionis tempore, propriis virihus in glohulam suam efformante.
Isto glohnlo intense viridi cx loculo demisso novam plantam
emittentc.”
This definition of IM. Leon le Clerk is exceedingly faulty.
I t Is not in each cell tha t the round globule is formed, hut only
in occasional cells, or at most in alternate cells ; and the assertion
that this globule really gives origin to a ncAV plant, is
by no means established. Even M. J . Deeaisne, Avho has
separated the Conjugateoe. from the Algæ zoosporæ of Agardli,
does not state that he has witnessed their developement, but
infers this from the fact that the filaments of the Conjugateoe,
Avhether young or old, in the same species, invariably present
the same diameter, and thus, as he supposed, could not proceed
from organs so minute as the zoospores.
M. Deeaisne combats the idea of the disintegration of the
sporangia of the Conjugateoe and Vesiculiferoe into zoospores, by
the fact tha t their contents are at all times fluid. This argument
is, hoAvever, by no means conclusive, the contents of
the cells of the Vesiculiferoe, &c., are also generally fluid ; but
this fluid, Avhen the proper period arrives, becomes fashioned
into distinct organs or zoospores, and the same may be the
case Avith the contents of the spores of the Zygnemata, as
asserted hy Agardh.
M. Deeaisne also repudiates the idea of a double mode of
reproduction ; the spores he regards as the true ç,nd only re productive
bodies of those Algæ Avhlch posses^s them; b u t it
is perfectly certain the usual and most frequent method of
reproduction of the Vesiculiferoe is hy means of zoospores, and
this fact, of which I have so perfectly assured myself, leads
to adoption of one of the following views — either th a t the
large, oval, or spherical bodies of the Algæ, comprised in M.
Decaisne’s class of zoospores, are not in any Avay connected
Avith reproduction ; a view Avhich can scarcely be regarded as
probable, and opposed to th a t entertained by M. Deeaisne
himself; or th a t they as well as the zoospores do perpetuate
the species; in favour of which view the evidence can scarcely
be pronounced sufficient to remove all doubt of its correctness.
L ink has endeavoured to establish this genus under the
name of OEdogonium, which has been adopted by Kützing,
Avho thus imperfectly characterises it.
“ Trichoma simjjlex, membranaceum, flaccidum. Cellulæ
coelogonimicæ, gonidia minutissima mobilia continentes. Sper-
matia solitaria globosa fusca, epispermo duplici hyalino cincta,
cellulls inclusa.”
In this description no allusion is made to the mode of
formation of the sporangia, and none to the ringed apparatus
Avith which each fruit-bearing cell is provided.
Several other generic terms have been applied to certain
species of the genus Vesiculifera, such as Tiresias, Cadmus,
Zoocarpa *, &c. but all of them, so far as I can learn, are
Respecting the genera OEdogonium, Tiresias, and Zoocarpa, I have
obtained the following information : — In the “ Dictionnaire Classique,”
vol. xii. p. 78., Bory thus remarks on the genus OEdogonium. “ The genus
proposed by Link under this name appears to be the same as that which
Vaucher named Proliféra, for which we have adopted the name of
Vaucheria. In the remarks on Vaucheria, Bory states that it was wrong
of De Candolle to change the name of Ectosperma, which he proposes to
restore, and to confer the name of Vaucher on the genus Proliféra, that
appellation being founded in error ; and Guilleman in the 16th volume,
p. 268,, of the same work, under the head of Tiresias, observes — ‘ Our
co-labourer, Bory de St. Vincent, has established and described a new'
genus of the family of Arthrodece and o f the tribe of Zoocarpece, in which
he indicates as the principal species the Conferva hipartita of Dillwyn
(a Tyndaridea ?). The characters of this genus have been explained in
this Dictionary, vol. i. p. 597—1822.’ Since that time the genus has been
adopted by Fries, who has placed it amongst his Hydrophytes or Algæ ;
O