SEAWEEDS 469 



which is the narrow membranous frond, the " wings " referred to in its technical 

 name. 



Polysiphonia urceolata is a plant of dense, thread-like, rather stiff fronds, 

 growing either on rocks or Laminaria. On cutting through one of the stems, 

 it will be noticed that it is composed of six tubes round a central aperture : 

 the branches are jointed. There are more than twenty British species of this 

 genus. It possesses pitcher-like fruits, to be examined through the microscope 

 for their beauty. 



Chylocladia artioulata (parvula) is a remarkable seaweed, its name signifying 

 " jointed juice-branch." It is some 8 to 10 inches in length, jointed, each 

 cactus-like joint being filled with red gelatinous juice. 



Iridcea edulis is a striking seaweed, with fronds 9 or 10 inches long and 

 4 or 5 inches wide, shaped rather like a racquet. Under the water it is beauti- 

 fully iridescent. 



The Carrageen, or Irish Moss (Chondrus crispus) is a very common species, 

 growing on rocks. Its shape is like a stag's antlers, but it varies much in colour, 

 from greenish white and yellow to a dull purple. It was once used for food, 

 boiled down to a jelly, and considered very beneficial to invalids; also to 

 make a size for calico manufacturers, and as a fattening food for calves. I 

 have noticed it specially abundant in estuaries and the mouths of tidal rivers. 



The common Gigartina mamillosa is very similar, but has broader and 

 grooved fronds, rough to the touch, and with little tubercles or warts like 

 grape stones. 



Dulse (DILLISK or DILLOSK) (Rhodymenia palmata) is still eaten in Scotland, 

 Ireland, and on the West Coast of England. It is very common, dark red in 

 colour, with fronds about 2 inches long and J inch wide, roughly fan-shaped. 



Rhodymenia jubata is more slender, and ragged, in some parts deeply lobed. 



The Coralline (Corallina officinalis) is found everywhere, and is identified 

 by its chalky, stony-coated little joints. For many years it was a question 

 whether this was a seaweed or a kind of coral, but it is now known to be a 

 vegetable. Other Algae also have a similar power of secreting lime Jania, 

 for example, with its much shorter and slenderer branches, and Melobesia, 

 which grows in thin horizontal plates and masses. 



