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i-al one, and entirely exotic; for two species, recorded as British, are
only occasionally wafted to our shores from more distant regions.
They are therefore to be considered in the same light with certain
birds, which, upon the strength of visits, few and far between, have
been admitted into our Fauna.
A small group of this genus, found in the seas of China and Japan,
differ very much in several pai-ticulars. The individuals which compose
it are distinguished by very small nerveless leaves and terminal
receptacles. Their habit is very slender, and the air-vessels generally
oval or elongated. Could these be removed, Sargassum would then
be peculiarly well defined, by its ribbed leaves, axillary fructification,
and spherical vesicles. Such a separation is recommended by M.
Gaillon, but it can hardly be effected without more information than
we possess at present on the subject.
The generic name is derived from Sargaqo, or Sargazo, the Spanish
name for the masses of sea-weed found floating on the surface of the
ocean.
1. S a r g a s .s u m v u l g a r e . Tab. I.
Stem compressed filiform, leaves linear-lanceolate serrated, air-vessels
spherical pointless supported on a little flat stalk, receptacles racemose.
Sargassum vulgare, Ag . S p . A lg . v . 1. p . 3. S y s t. Ag . p . 293. S p r e n g . S p . P I . v . 4.
p . 320.
Fucus natans, T u r n . H is t. F u c . t. 46. S y n . p . 48. S m . E n g . B o t. t . 2114. L am o u r .
E s s a i, p . 15.
H a b . Cast on the shores of the Orkney Isles.—Mr P. Neill.
Root a small callous base. Stem above a foot long, alternately pinnated
with simple branches. Leaves dotted with pores, distichous,
alternate, two lines to half an inch broad, olive when growing, dark
red brown after exposure to the air. Receptacles cylindrical, about
two lines long. Vesicles neatly as large as a small pea.
Tliis, as well as the following species, has been found in almost
every part of the world, and is repeatedly alluded to by the old navigators
as occurring in such prodigious quantities in the Atlantic as to
appear like a boundless floating meadow, and actually to impede the
progress of the ships. Osbeck mentions, that, if prepared with vinegar,
it furnishes an excellent pickle; and Rumphius, according to
Mr Turner, relates, that, in the East, salads aré made of it, as well
as of other Algse. It is also eaten in Chili.
2 . S a rg a s s um b a c c i f e r u m .
Stem cylindrical filiform much branched, leaves linear acute serrated,
air-vessels spherical on little cylindrical stalks.
Sargassum bacciferum, Ag . S p . A lg . v . 1. p . 6. S y s t. A lg . p . 294. S p r e n g . S p , P I . v . 4.
p . 320.
Fucus hacciferus, T u m . H i s t . F u c . t . 47- S y n . p . ,55. Sm . E n g . B o t. 1 . 1967. L am o u r .
E s s a i, p . 16.
Fucus natans, L in n . S p . P I . 1628.
H a b . Cast ashore by the waves. It has been received by Mr P.
Neill from the Orkney Isles along with the preceding; and Mr W.
Backhouse junior has gathered it at the foot of Castle Eden Dean,
Durham.
Stems much more branched than in the former species; the branches
irregular, and much longer. Leaves about a line wide, varying greatly
in length, and destitute of pores. Air-vessels generally, but not always
mucronate. Receptacles unknown.
Both this and the preceding species exhibit several varieties, characterised
chiefly by the size or slenderness of the frond and leaves.
It is not a little amusing to see the air-vessels gravely described as
the fructification, in the sixth edition of Withering’s Botanical Arrangement.
G e n u s II. CYSTOSEIRA, Ag. Tab. II.
G e n . C h a r . Frond furnisbed with brancli-like leaves, becoming
more filiform upwards; air-vessels simple, arranged
consecutively wdthin tbe substance of the branchlike
leaves. Receptacles cylindrical, more or less lanceolate,
tuherculated, terminal. Seeds in distinct cells.
This genus, like the preceding one, formed a section of the Fucus
of Lamouroux, but was removed by Agardh, and established as a
distinct genus in his excellent Species Algarum. I agree, however,
with M. Gaillon, that it would be rendered more perfect by the exclusion
of various individuals, which in reality have little affinity with
the remainder, and of themselves furnish types for several new genera.
The lower leaves of the species of Cystoseira, as I have modified
the genus, are either dichotomous or pinnatifid, and, when not cylin-
A 2