Plate I. 
Fig. 1. SARGASSUM VULGARE. 
Colour. When fresh, olive ; when dry, reddish brown. 
Suhsta7ice. Tough, leathery. 
Character of Frond. Stem and branches. Branches on each side the stem {pinnate) ; alternate ; 
bearing distinct leaves. Leaves midribbed ; oblong ; toothed like a saw {serrated) at 
the edges ; generally marked with minute dark dots {pores). 
Measurement. From 12 to 18 inches long. Width of leaves, variable. 
Air-vessels. Like tiny round balls, borne on flat stalks, springing from the angles of the 
branches {axillary). 
Fructification, Minute seeds (properly called spores) in special receptacles ; several on a 
branchlet just above the air-vessel. 
Habitat. Atlantic Ocean. Tropical and sub-tropical coasts. Florida, Syria, &c. Drifted to 
our shores by oceanic currents ; but very rarely. 
Fig. 2. SARGASSUM BACCIFERUM. 
Colour. When young, pale olive ; clear ; in age, foxy ; when dry, black. 
Substance. Tough, leathery ; when dry, brittle. 
Character of Frond. Stems and branches. Stems angularly bent. Branching irregular ; 
sometimes from a central point in all directions. Branches bearing distinct leaves. 
Leaves midribbed, extremely narrow {linear-lanceolate) toothed like a saw {serrated) 
at the edges ; without dots {poises). 
Measurement. Indefinite ; as it is found in masses, without a root. 
Air-vessels. Like tiny round balls, smaller than in S. vulgare ; generally tipped with a spine- 
like point, sometimes short, sometimes long ; occasionally, without. 
Fructification. Very rarely found. Like that of S. vulgare. 
Habitat. Tropical and sub-tropical ocean, in both hemispheres ; always floating. 
This is the celebrated Gulf-weed which stayed the ships of Columbus. No root has ever 
been found on it. Its growth is by young branches sprouting from old broken ones. Forming 
ridges (or banks, as they are called) in the sea, from 10 to 20 yards wide, and of indefinite 
length. 
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