Plate I. 



Fig. 1. SARGASSUM VULGARE. 



Colour. Wlieii fresli^ olive; when dry, reddish brown. 

 Sithstance. Tough, leathery. 



Gharadcr of Frond. Stem and branches. Branches on each side the stem 

 {pinnate); alternate; bearing distinct leaves. Leaves midribbed; ob- 

 long; toothed like a saw {serrated) at the edges; generally marked 

 with minute dark dots (j)orc.9). 



Measurement. From 12 to 18 inches long. Width of loaves, 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. 

 Sid)stance. 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 {pores). 



Measurement. Indefinite; as it is found in masses, without a root. 



Air-vessels. Like tiny round balls, smaller than in 8. 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. 

 1 B 



