6 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Description. In more or less cylindrical or slightly flattened or 

 bent pieces of variable length and 10 to 20 mm. in thickness; exter- 

 nally, grayish-brown or dark brown, longitudinally furrowed and 

 wrinkled; fracture tough, horny; internally, dark brown having a 

 slight saline odor and a mucilaginous, slightly saline and bitter taste. 



Inner Structure. The stipes show two well-differentiated layers, 

 an outer one of narrow cells with brownish walls, and a middle por- 

 tion consisting of very long hypha>like cells, with thick, porous, 

 mucilaginous walls. The cells contain numerous brown chromato- 

 phores, the brown pigment of which is soluble in water, leaving the 

 green chloroplasts unaffected. 



Constituents. About 47 per cent of mucilage; tangic acid 19 

 per cent; cellulose 11 per cent; ash 13 per cent, of which two-thirds 

 is soluble in water; iodin from 0.06 to 0.11 per cent. The iodin is 

 apparently combined in an organic form and is soluble in water, 

 alcohol, acetone, alkalies and acids. Tunmann was able by means 

 of very clever technique to detect microchemically the presence of 

 iodin in 0.001 to 0.002 gm. of Laminaria. Sections of the fronds 

 were placed in conjunction with starch upon slides and strong nitric 

 acid added, the liberated iodin unites with some of the starch grains, 

 staining them a blue color. 



Literature. Tschirch, Handbuch der Pharmakognosie. 



PREOPHYCE-E, OR BROWN ALG^ 



Fucus. Bladder Wrack. The entire, dried plant of Fucus ve- 

 siculosus (Fam. Fucacese). A common seaweed growing on rocks near 

 the coast of the northern countries bordering the Atlantic Ocean. 

 The fruiting plants are most active and are collected in autumn, 

 although fructification continues during the winter, or may be seen 

 to some extent at any time during the year. According to Farlow 

 in his monograph on " The Marine Algae of New England," there are 

 several varieties of Fucus vesiculosus, depending upon the character 

 of the fronds and receptacles. 



Description. Fronds dioecious, 20 cm. to 1 meter in length; 

 dichotomously branching with a distinct midrib throughout; margin 

 entire and often wavy, sometimes repeatedly forked or in some 

 varieties short or spirally twisted ; on either side of the midrib occur 

 vesicles containing oxygen and which vary from spherical to ellipsoidal 

 in shape. The receptacles, containing either oogonia or antheridia, 

 are terminal, swollen, ellipsoidal or oval, often forked; the color when 

 fresh, olive-brown becoming blackish-brown on drying; somewhat 



