Some few ilriftures upon the theoiy of Gsertner, as relative to the propagation o f the confervas;,
will clofe thefe remarks.
A proper generic diilinftion between the fucus and conferva does not yet appear to be eftabliihed, as
the charaaers o f both genera are fometimes blended together. The tranfverfe diaphragms and-joints,
the tenuity and capillary ftruaure, are the common obvious marks o f diftinaion in the confervas. Y et
we find fome fpecies o f the latter defcribed as not being jointed ;-[• while fome of the fucufes are fur-
niihed with diaphragms. The genus ulva ftill adds to the confufion, by fometimes partaking of the
properties peculiar to each of the former. The Ulva capillaris of Hudfon, for inftance, has been frequently
found with fpherical veficles in great abundance at the extreme branches; in. which may be difcovered
feveral pear-ihaped grains or feeds, hardly differing in colour from the reft o f the plant: from
this circumftance it might rank ^^'ith the fucus. The Ulva articulata, in its jointed appearance, approaches
very nearly to the charafter o f the conferva; while the Fucus Filum exhibits a feries o f diaphragms,
which might juftify its being added to the laft-mentioned genus. The Fucus incurvus feems
to unite the diftinftions o f both genera : for the pinnulas, in the recent plant, when held to the light,
frequently difcover a regular courfe of feptas, which are not to be obferved in the other parts o f the
fucus. The inflated leaves o f the Fucus filiquofus, which from their ftrong refemblance to pods,
have furniihed this plant with its trivial name, are fubdivided by diaphragms that are even palpable.
It has frequently been remarked, that Nature proceeds, as by a regularly extended chain, from
plants o f the moft fimple and unorganized ftate, to others, which from being more complex in their
ftru£lure, are therefore deemed more perfeil. This favorite idea o f a connecling feries, feems to’
have been followed by a more appofite comparifon of an ingenious author,^ who obferving in how
clofe and infeparable a manner the orders o f Nature are fometimes blended together; illuftrates the
procefs by a metaphor, drawn from the interwoven mefhes of a net, which are united together by a
multifarious connexion. Without contending for the juftnefs o f the application to the plants in queftion,
and which are reckoned among the primary and moft fimple o f the Natural Orders: '* certain it
is, that the conferva, ulva, and fucus, are not at prefent feparated by fixed and permanent generic
diftinflions, and that they fometimes participate in properties peculiar to each.*
Gccrtner readily admits that the more perfeft fucufes are produced from feeds, and as confidently
maintains, that the extenfive genus o f confervas derive their propagation, from a totally-different
fource: and that, in feveral fpecies o f the latter, it is effe6ied foleiy by the fmall lateral filaments,
which from intumefcence affume the form o f globules, and falling off fpontaneoufiy from the branches,
become in their turn, the fources o f a proliferous increafe.“
There are, however, beyond a doubt, many confervas, which at particular feafons produce opaque
granulated veffels or feeds, contained within thofe very globules, probably, which this author mentions
T See C. rivularis, C. faenlculacea, &c. FI. Scot. ^ Donati.
J4 -Pianti omnium imperfcftiflimiByni ct Conferva:—in quibus Natura primordium inftituiffc vidctur.” Gmcl. Ilift. Fucor. p. 35.
* The U lva articulata, notwithftanding iis ftriking refemblance to ilie conferva, is confidered by Lightfoot as ufucus. The Con ter va fiftulofi
of Dillenius, t. 6./. 39. (i. c. C. lubulofa of Fludfon) is placed under the genus ulva by Linneus. See Ulva confcrvoides. Sp. PI. 1632.
>5 • hac fimplici formantur mcthodo ut nunc unicus, nunc duo fibi proximi, latcralium filorura articuli, per incram fubflantite fui earnofr
imumcfcentiam, in unicum globulum folidura convertaiilur, qui poftga fpontc dccidit, cl dim cx altera parte fcopuiis aa^lutinatur, ex altera novum,
frudit aniculum". Gin. dc Fruii, p. j 6. I,
tions as being in themfelves, the original and only fource of increafe. He has unfortunately fixed
upon the C o n f e r v a corallinoides— a fpecies, of all others, leaft favourable to his hypothefis. This
conferva is of fo fimple a texture, that it has the appearance o f a fine tubular tranfparent membrane,
which at length acquires a beautiful crimfon fluid. In this ftate, it is fometimes, but not frequently
difcovered with dark clufters or protuberances furrounding the joints (as noticed by Mr. Lightfoot).
Thefe when under a microfcope, are found to contain a great number o f dark purple ovate veffels;
but whether the latter are feeds, or only pericarps containing more minute particles, docs not appear.
I f the plant at this time be placed between papers, it will foon difcharge its interior crimfon fluid,
leaving only a jointed tranfparent film, the veffels at the joints excepted, which retain a degree o f fo-
lidiiy and opacity, very different from the other part o f the plant. Now as thefe granulated bodies
are fo very diftinft from the internal fubftance o f the conferva ; it is highly probable, they are formed
by that procefs and peculiar reparation of the general mafs, on which Grertner fcientifically eflab-
liflies the origin of feeds— in contradiftinaion to the Ample increafe o f medullary fubftance, on which
he has founded the principle o f propagation by gems.”’ In fliort, that by a fecvetion o f the fluid, an
entire new organized body is formed; or, in other words, the pericarps or feeds. I f then, according
to this authors mode o f reafoning, the grains contained in the more perfea fucufes are aaual feeds,
and the fources o f increafe— it ihould follow, from the inftance juft given, and from others which
might be produced, that the confervas alfo, derive their propagation from the fame principle.
This opinion fliould feem more probable than that laid down by Gasrtner, becaufe the origin o f all
thefe plants is imperceptibly fmall; fince we find them growing upon the fmootheft and moft gloffy
furfaces of plants, and as frequently upon the fineft capillary branches of fucufes, full as minute as
the confervas that are attached to them. In thefe fine branches, however, there muft be fome nidus
or repofitory, fufficiently capable o f affording flielter and proteftion to thofe minute feminal atoms,
which efcape from veffels fimilar to thofe before defcribed. Neither is it eafy to conceive in what
manner the mode of propagation could fucceed, according to Gzertner’s theory: for as the confervas
are frequently o f an equal fize with thofe branches which fupport them, it is by no means probable,
that the jointed globule o f a conferva (if this may be the author’s meaning) could fo inftantaneoufly
attach itfelf to fuch a body, and with tenacity fufficient to refill the conftant collifion o f tides.
That the globules confili o f the medullary fubftance o f the plant itfelf is readily admitted : at the
fame time^ it mull be allowed, that all the confervas, which produce the granulated veffels or feeds
imbedded in thofe globules, bear a ftriking refemblance, in their mode of propagation, to the more
perfe£l fucufes ; and not being apparently fubjefl to the laws o f florefcence, attain their ftate o f fructification
in a manner exaflly fimilar to that, which has been afcribed to the latter : from an inherent
fclf-efiicient principle, equivalent indeed, though entirely different to that, on which the fexual dif-
tinftion is founded.
D
It might be almofl fufpeilcd from the above palhige, that Girtnerhad too haflily embraced the opinion of Adanfon, without having duly attended to
thofe plants, through the différent liages of their growth.— “ On peut dire que datis le Conferva même, qui n’ a point de graines. 1’ articulation qui
en tient lieu, cil analogue aux Embrions inonocotulcdons, puifqu'elle vegete d'abord par un extrémité qui fert de racine, en s’appliquant à divers
corps, et enfuile par l'extrémité opafée qui forme des tijes." Adans. Fam. Plant, par. 1. p. 304.
15 " Quod gemmi medulla, fit/law meditili materni ; dum contra fcminis medulla, non pofhtnon effe novifiìma ct a matrisfuæ dillincliffima.’'
Goeri. de Frudl. p. 9.