BRIGHT-COLOURED ALG.E. 131 



are often of great length, s extending to twenty and 

 even forty feet, and resembling a cord of leather 

 or gutta-percha. In some parts of the coast, 

 especially of the Orkney Islands, this plant grows 

 in great profusion, forming a sort of marine 

 meadow through which a boat forces its way with 

 some difficulty. The cord or string of which it 

 consists is a hollow tube, divided into chambers 

 filled with air, which renders the whole plant 

 very light, and enables it to float upwards to the 

 top, and along the surface of the water. More 

 than fifty species, all differing more or less from 

 each other, are enumerated by marine botanists 

 as comprehended in the series of the Melano- 

 spermese. 



We shall now notice a few specimens of the 

 Ehodospermese. These plants are generally of a 

 rose, purple, or red-brown hue, and many of the 

 varieties, which are numerous, are extremely 

 beautiful, especially those of a pink colour. 



" Their blushes speak 

 Of rosy hues that o'er the ocean break 

 When cloudy morn is calm ; yet fain to weep, 

 Because the beautiful are still the frail." 



One of the most elegant of these plants is the 

 scarlet plocamium (Plocamium sanguineum), 

 with which most visitors of the sea-shore are 

 familiar. It is of a fine pink colour. The fronds 

 are much branched, and are feathery in their 

 structure, the smaller branches being furnished 

 with minute subdivisions like the teeth of a comb ; 



K 2 



