F U C U S. 89 
of the fuel or fea-^veecis being \ifed for this piirpofe.] In 
botany, a genus ot t!>e dal's cryptogamia, order algae ; 
comprehending moll of thofe plants known by the name 
of Sfa-VVeeds. The generic charaders are—Seeds pro¬ 
duced in cindered tubercles, which burfl at their fum- 
niits.—Of this genus, fifty eight fpecies are enumerated 
in the fourteenth edition of Syjlema Vegetabilium. Sixty- 
eight Britifli fpecies, befides many vari^fies, are enume¬ 
rated in Dr. 'Withering’s Botanical Arrangements ; and 
feventy-two have been more recently deferibed by Dr. 
Goodenough and Mr. Woodward, in the Linnaean Tranf- 
a^li>'ns, vol. iii. Turton, collefling from the refearches 
of all botanifts, gives a catalogue of one hundred and 
forty-nine fpecies. A great deal of uncertainty and 
doubt is dill attached to this genus of plants, concerning 
the frudlification, and peculiar mode of propagation. 
See the article Botany, vol. iii. p. 283-288, wherein 
this fubjedl has been already difcufled. We diall how¬ 
ever add, in this place, the ingenious obfervations of 
Dr. Goodenough and Mr. Woodward : 
“ In many fuci, two forts of frudlification are to be 
feen—one warty tubercles, and the other numerous fingle 
grains. The obfervation of thefe has led young botanids 
to imagine that they are the differences of fex. Un¬ 
doubtedly both thefe appearances are of the female 
flower, i.e. feminal. 'We have obferved them occa- 
fionally in F. alatus, vermicularis, and hypogloffon, feat- 
tered along tlie rib or nerve, or on the membrane on each 
fide of it. Some few of thefe grains we have obferved 
fwelling apparently into a tubercle, and the others difap- 
pearing. 'Whether this be the mode of perfedling the 
frudlification, and that fuch of thefe grains as are im¬ 
pregnated fwell into feminiferous tubercles, whilll the 
reft are abortive and decay ; or, whether thefe grains may 
not be real feeds efcaped from a tubercle, the coats of 
which are burfl, and adhering to the frond, it were to be 
wilhed that naturalifts refident on the fea-fide would exa¬ 
mine and endeavour to determine. The tubercles of the 
greater part of the fuci open at the point, are imbedded 
in the fubftance and become fwollen, as in F. ferratus, fpi- 
ralis, &c. or affume a broad warty form, as in laceratus 
and fome others; are imbedded, fmooth, and veficuli- 
form, as in crifpus, &c. projedl very much from the 
frons, as in coufervoides; or are fituated in a peduncu- 
lated capfular procefs, as in filiquofus, pedunculatus, &c. 
“It h.is been the general opinion of naturalifts, that 
the root of fuci is an organ of-adhefion only, and not of 
nutrition. It feeins fo admirably calculated for the for¬ 
mer of thefe purpofes, that probably this idea has pre¬ 
cluded all confideration of the latter. How the vegeta¬ 
tion is carried on, cannot be precifely afeertained ; and 
althopgh it'does not feem likely-, that the root fhould 
draw nourifhment from the rock, ftone, or other body 
to which it is affixed, in the fanie manner as the roots of 
terreftrial plants from the earth in which they grow ; yet 
it would be difficult to affert and bring proofs, that while 
it fixes, it does not alfo alTift to nourifti.—They are prin¬ 
ciples by no means incompatible. It is very poffible, 
that the element in which thefe plants grow, may be im¬ 
bibed at numberlefs minute pores on the furface of the 
frons, imperceptible to our fight, and that thefe pores 
may be common to the root with the reft of the plant; ' 
and thus the divine will may be accomplilhed. 
“ All fuci appear to proceed from a thin, round, entire 
br filiiie, glutinous, coriaceous fubftance: this will ap. 
pear to any one who will watch the growth of F. loreus. 
In fome few this fubftance is fiffile, and imitates the fibres 
of land plants: but each fibre attaches itfelf by its ex¬ 
tremity, which immediately becomes a flat difk, to fome 
rock, and, if the rock be fmooth, longitudinally alfo. 
Gmelin’s idea of the root does not accord with this fact. 
He fays, that thofe fpecies which are thin and papyra¬ 
ceous, have never Ihewn any appearance of root. Never 
was there a more palpable miftake. The root in all of 
them is a flat dilated difle, more or lefs in proportion to 
Vol. VIII. No. 486. 
the fize and fubftance of the plant. One of the thinneft 
and moft tender produ6lions, F. laceratus var. laciniatus, 
has not only this kind of root, but fometimes for the 
fpace of two or three lines,, has a roundilh ftalk before it 
is dilfolved into its thin laminae or branches. The root 
is either purely fibrous, as in faccharinus, or between fo- 
lid and,fibrous, as in ferratus, where a tendency to fibrous 
divifion is obfervable; but the fibres, which are fome- 
what prominent upon the furface, are webbed as it were, 
or connefled by a thick membrane or the intervening 
part of the difk ; or laftly, which is by far the mod nu¬ 
merous, an entire folid difk. There are different modi¬ 
fications of this laft fort of root. Sometimes, as in fili- 
quofus, if becomes in its more advanced age a folid woody 
cone; fometimes a plant having fprung from its difk, 
conftantly throws out from its very bafe clufters of little 
furculi, which accidentally touching the rock form a cal¬ 
lus, by which as by a new diik it adheres, and thence be¬ 
comes the parent of a new plant. Its original, from a 
finall difk, is thus fo covered over and obfeured, that it 
is not to be difeerned. This takes place particularly in 
F. piirpurafcens, which hence is generally deferibed with 
a filirous root, as fhewn in the Engraving. From this 
furlofiiy at the bafe, and the furculi occalionally form¬ 
ing new difks and new plants, fome fuci appear to have 
creeping roots. 
“ The F. natans is deferibed by Linmneus, libere natans 
nec radicatus. Thefe words miift be underflood to mean 
Jloating at large, and not fajlened by any root. He never 
could mean, having no root for his own fpecimen in the 
herbarium has one, which is a difeus explanatus, and ap¬ 
pears to have a very flight power of adhefion. It may be 
prefumed that it is an inhabitant of the deep waters, be¬ 
yond the reach of human fight. Storms and tempefts, 
diflodging it from its native bed, bear it in their uncon¬ 
trollable violence to all the fhores of the known world. 
F. bulbofusis a plant fuigeneris \ the difk immediately af- 
fumesan inflated bulbous form, the bulb becomes cover¬ 
ed with numerous excrefcences, which require very mi¬ 
nute inveftigation. The afeertainment of its oeconomy in 
this particular, as alfo of its fruclification, would be a 
fiibjedl of very curious enquiry. All plants produced 
from thofe rudiments of new branches obfervable on the 
iweioizz ai mammillofus, rubens. See. muft neceffarily have a 
plain difeoid root, that being the caufe of their firft adhe¬ 
fion. 
“ Great variations in the fame fpecies of fucus, will 
often arife from two caufes, from the mutilations which 
ihey fuffer from the violence of the waves, or other inju. 
ries, and their growing nearer, or more remote from, the 
deflux of frefh water. A very frequent effedl of external 
injury is the proliferous or reprodudlive tendency which 
is thereby occafioned, and which often fo alters the natu¬ 
ral appearance of the plant, as to entirely difguife it to the 
eye of an unpradtifed obferver. This is extremely fre¬ 
quent in F. finuofus, when the membranous parts are de- 
ftroyed, and only the nerves or fibres remain, from which 
young leaves are frequently feen to fhoot in great abun¬ 
dance, giving it an appearance fo entirely different from 
that which it at firft had, that it might eafily be fuppofed 
a different fpecies, did not the frequency of this plant af. 
ford us an opportunity of feeing it in all its varying forms. 
The F. rubens perhaps owes fome of its appearances to 
this caufe; for the young plants are at firft entire, and 
thofe of a more advanced growth fhew fometimes much 
lefs appearance of this proliferous tendency than others t 
but we cannot, in this fpecies, attribute the whole of 
the particular habit to thefe accidental caufes. Injuries 
done to the hardier fpecies may be more readily traced in 
their eft'edls; F.inflatus is one inftance of this, wliichis 
probably nothing more than with a branch in¬ 
flated or fwollen by the injury of fome infedt or outward 
violence. The vejiculofus v&r. foliaceons, affords one of the 
moft remarkable inftances of'reprodudlion occafioned by 
external violence. This was firft noticed by Major 'Vel- 
