ALG.E 7 



cartilaginous, having a saline odor and a mucilaginous, somewhat 

 saline and nauseous taste. 



Inner Structure. The tissues consist for the most part of a 

 pseudo-parenchyma, the cells upon the outer surface of the thallus 

 being somewhat smaller and arranged in close tangential rows, 

 while those distributed throughout the central portion are hyphse- 

 like and with thick mucilaginous walls. The cells contain a brown- 

 ish protoplast, the coloring principle of which is soluble in a hydro- 

 alcoholic solution. If the material is first treated with a saturated 

 solution of sodium chloride and alcohol then added, the chlorophyll 

 may be extracted. 



Constituents. From 22 to 62 per cent of organic substances, con- 

 sisting mostly of mucilage (algin) and a peculiar cellulose; 0.5 per 

 cent of mannite; 0.1 per cent of a volatile oil, to which its odor is 

 partly due; from 3 to 16 per cent of ash, containing both iodin and 

 bromin. The ash contains from 0.7 to 1 per cent of iodin. 



Allied Plants. Fucus serratus, a very common species of Europe 

 but very rare on our coast. It grows in deeper water than F. vesi- 

 culosus and is easily recognized by the serrated margin of the thallus 

 and the absence of bladders. The receptacles are also serrate, con- 

 siderably flattened, and acute at the summit. Its composition is 

 similar to that of F. vesiculosus. 



A number of other species of Fucus, besides those mentioned 

 as well as other Algse, are gathered under the name of kelp off the 

 coast of Cherbourg, France, and Glasgow, Scotland, and are used as 

 a source for the production of iodin and bromin. 



RHODOPHYCE.E, OR RED ALG^E 



CHONDRUS. Irish Moss or Carrageen. The entire plant of 

 Chondrus crispus (Fam. Gigartinacese), a common red alga found 

 along the northwestern coast of Ireland and the coast of Massa- 

 chusetts. The plants are collected chiefly during June and July, 

 spread out on the beach and bleached by the action of the sun and 

 dew, then treated with salt water, finally dried and stored. The 

 chief points of collection in this country are 15 to 25 miles south of 

 Boston. 



Description. Consisting of a number of dichotomously branch- 

 ing, somewhat enlarged segments, becoming emarginate or two- 

 lobed, which arise from a slender, somewhat flattened base about 

 one-half the length of the entire thallus; yellowish-white, trans- 

 lucent; sometimes with fruit-bodies or sporangia embedded near 



