CHONDRUS. IRISH MOSS. CARRAGHEEN. 209 



cent., and i to 2 per cent, of ash, are the constitutents. 

 Lichenin is colorless and tasteless, soluble in boiling 

 water, forming a jelly on cooling. Cetraric acid, or 

 cetrarin, is bitter, cr\'stalline, almost insoluble in water, 

 soluble in warm alcohol and ether; forming salts with 

 bases soluble in water. Lichen-stearic acid is crystalline, 

 insoluble in water, Soluble in alcohol and ether. 



CHONDRUS. IRISH MOSS. CARRAGHEEN. 



''Chondriis crispus, Stackhouse, and Gigartina mam- 

 illosa, J. Agardh (class Algae)." U. S. 



These closely related Algae are found on the rocks on 

 the shores of the Atlantic Ocean, in Europe, from North 

 Cape to Gibraltar; in America, along our eastern coast. 

 They are collected in the spring from the Irish and New 

 England coasts. 



Description. — Arising from a disk-like base, the frond 

 of Chondrus crispus enlarges and flattens, then either 

 divides dichotomously into numerous linear, slightly 

 wedge-shaped lobes, or into fewer broad irregularly wavy 

 marginate segments. Forms intermediate between these 

 two are also common. The cystocarps are imbedded near 

 the ends of the lobes; they project slightly, sometimes 

 showing a small aperture. Gigartina mamillosa is 

 similar but more irregular. The crystocarps, distributed 

 along the grooved branches, are oval and raised on a 

 short peduncle. 



Histology. — The two faces of the frond show each a 

 comparatively broad layer of regularly arranged thick- 

 walled cells with minute cavities. Within these are the 

 larger cells of the body of the frond, growing more ir- 

 regular toward the centre. The contents of these are 

 granular. Zinc chlor-iodide colors the inner lamella 

 of the cell-wall blue, the granular brown, and the mucilage 

 slightly rose-red. The crystocarps consist of large 

 numbers of round or oval well-filled spore sacs. 



M 



