z86 BO T 
to light, and from the upper part extends itfelf into a new 
joint; till at length it grows up, into the ex aft form and 
fimilitude of the proliferous parent plant. Thefe globules, 
Gaertneroblerves, have a very ftrong refemblance to the 
frudified parts of plants, in their texture as well as in their 
form and colour; yet, upon examination, he affirms, they 
will be found to be fimple germens, confiding of mere me¬ 
dullary fub(lance, contained in a homogeneous bark or co¬ 
vering : from which circumftance, as well as from the 
confluence of thofe joints into a globule, he maintains, 
that they do not depend upon any other principle than the 
fimple faculty of vegetation for their mode of increafe. 
But although Gaertner alT’erts that the confervas, as well 
as all thofe fucufes which are membranaceous, are fubject 
only to a proliferous mode of increafe ; yet we have the 
cleared proofs, that many of the latter derive their pro¬ 
pagation from feeds, in every refped as unequivocally as 
thofe fucufes, which have been deemed more perfect. 
The fucus.rubens, i. e. the crenatus of Gmelin, is truly 
membranaceous, very thin in its texture*, and nearly tranf- 
parent. The central nerve, which pervades the frond, 
frequently branches off' in oppofite directions, producing 
numerous leaves, which at fird fight may appear as the 
deciduous offsprings of the proliferous parent (lock. . The 
margins of thefe leaves are oftentimes clofely fringed with 
minute (pines; -each of which in time becomes a kind of 
capfule, containing many feeds of a faint purple colour. 
.Not one of thefe feeds, when magnified, appears much 
larger than a particle of fund. The fucus crifpatus of 
Hudfon, although as delicate in its texture as the fined 
ulva, contains wntliin its fegments minute innate veficles, 
which abound with a remarkable quantity of grains or 
feeds, in every refped very fimilar to thofe, which are 
obferved in the perfed plants of this genus. Several 
other membranaceous fucufes, which have been (in the 
Syd. Nat.) lately feparated from the red, as being Atp- 
pofed fubjed only to a proliferous increafe; leave us no 
reafon to imagine that they are defiitute of feeds. Even 
Gmelin, who (in Hid. Fucor.) feems fird to have eftablidi- 
ed that divifion, defcribes a plant of this order, the mar¬ 
gins of which were furrounded with opaque globules : 
and, without being prejudiced in favour of his former opi¬ 
nion, candidly endeavours to account for the eaufe of this 
appearance, by attributing it in fome degree to a date of 
maturefcence : which, according to the more ordinary 
cotirfe of nature, had produced thofe repofitories for 
feeds, on which the propagation of the fpecies might pro¬ 
bably depend. 
“ A proper generic didindion between the fucus and 
conferva does not yet appear to be edablifiied, as the cha¬ 
racters of both genera are fometimes blended together. 
The tranfverfe diaphragms and joints, the tenuity and ca¬ 
pillary drudure, are the common obvious marks of dif- 
tindion in the confervas. Yet we find fome fpecies of 
the latter deferibed as not being jointed ; while fome of 
fhe fucufes are furnillied with diaphragms. The genus 
Ulva dill adds to the confufion, by fometimes partaking of 
the properties peculiar to each of the former. The Ulva 
capillaris of Hudfon, for indance, lias been frequently 
found with fpherical veficles in great abundance at the ex¬ 
treme branches ; in which may be difeovered feveral pear- 
fhaped grains or feeds, hardly differing in colour from the 
red of the plant: from this circumfiance it might rank 
with the fucus. The Ulva articulata, in its jointed ap¬ 
pearance, approaches very nearly to the character of the 
conferva : while the Fucus filum exhibits a feries of dia¬ 
phragms, which might jufiify its being added to the lad- 
mentioned genus. The Fucus incurvus feems to unite the 
diftindions of both genera ; for the pinnulas, in the recent 
plant, when held to the light, frequently difeover a regu¬ 
lar cotirfe of feptas, which are not to be obf'erved in the 
other parts of the fucus. The inflated leaves of the Fucus 
filiquofus, which from their drong refemblance to pods, 
have furnidied this plant with its trivial name, are fubdi- 
vided by diaphragms that are even palpable. 
A N Y. 
“ It has frequently been remarked, that Naiure pro¬ 
ceeds, as by a regularly extended chain, from plants of 
the mod fimple and unorganized date, to others, which, 
from being more complex in their drudure, are therefore 
deemed more perfed. This favourite idea of a conneding 
feries, feems to have been followed by a more appofite 
companion of an ingenious author, who obferving in how 
dole and infeparable a manner the orders of Nature are 
fometimes blended together, illudrates the procefs by a 
metaphor, drawn from the interwoven meflies of a net, 
which are united together by a multifarious connedion. 
Without contending for the judnefs of the application to 
the plants in qtiedion, and which are reckoned among the 
primary and mod fimple of the natural orders : certain it 
is, that the conferva, ulva, and fucus, are not at prefent 
feparated by fixed and permanent generic diftindions, and 
that they fometimes participate in properties peculiar to 
each. The Ulva articulata, for infiance, notwithdanding 
its finking refemblance to the conferva, is conlidered by 
Lightfoot as a fucus; the Conferva fidulofa of Dillenius, 
t. 6. f. 39. (i.e. Conferva tubulofa of Hudfon,) is placed 
under the genus ulva, by Linnaeus. 
“ Gaertner readily admits that the more perfed fucufes 
are produced from feeds, and as confidently maintains, that 
the extend ve genus of confervas derive their propagation 
from a totally different fource ; and that, in feveral fpe¬ 
cies of the latter, it is effeded folely by tlie (mall lateral 
filaments, which from intumefcence affume the form of 
globules, and falling off fpontaneoudy from the branches, 
become, in their turn, the fources of 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, pro¬ 
bably, which this author mentions as being in themfelves, 
the original and only fource of increafe. He has unfortu¬ 
nately fixed upon the Conferva corallin0id.es; a fpecies, of 
all others, lead favourable to his by pothefis. This con¬ 
ferva is of fo fimple a texture, that it has the appearance 
of a fine tubular tranfparent membrane, which at length 
acquires a beautiful crimfon fluid. In this date, it is fome¬ 
times, but not frequently difeovered, with dark cinders or 
protuberances furrounding the joints. Thefe, when un¬ 
der the microfcope, are found to contain a great number 
of dark purple ovate velfels ; but w hether the latter are 
feeds, or only pericarpiums containing more minute par¬ 
ticles, does not appear. If the plant at this time be pla¬ 
ced between papers, it will foon difeharge its interior crim¬ 
fon fluid, leaving only a jointed tranfparent film, the vef¬ 
fels at the joints excepted, which retain a degree of 1'oli- 
dity and opacity, very different from the other part of the 
plant. Now as thefe granulated bodies are fo very dillindt 
from the internal fubdance of the conferva pit is highly 
probable, they are formed by that procefs and peculiar 
reparation of the general mats, on which Gaertner feienti- 
fically edablilhes the origin of feeds; in contradidifidion 
to the fimple increafe of medullary fubftar.ee, on which 
he lias founded the principle of propagation by germens. 
In fhorr, that by a fecretion of the fluid, an entire new or¬ 
ganized body is formed; or, in other words, the pericar¬ 
piums or feeds. If then, according to this author’s mode 
of realoning, the grains contained in the more perfect fu¬ 
cufes are adual feeds, and the fources of increafe, it fliould 
follow, from the indance juft given, and from others which 
might be produced, that the confervas alio derive their 
propagation, front the fame principle. 
“ This opinion fhould feem more probable than that laid 
down by Ga.'rtner, becaule the origin of all thefe plants is 
imperceptibly fmall; fince we find them grow ing upon the 
fmootheft and mod gloll'y furfaces of plants, and as fre¬ 
quently upon the fined capillary branches of fucufes, full 
as minute as the confervas that are attached to them. In 
thefe fine branches, however, there mud be fome nidus or 
repofitory, diffidently capable of affording Ihelter and pro. 
tedion to thofe minute feminal atoms, which efcape from 
veffels fimilar to thofe before deferibed. Neither is it ealy 
to 
