ZOSTERA, OR GRASS WRACK. 81 



The marine plants which occupy sandy shores are not 

 numerous, though a great variety of beautiful kinds may 

 often be picked up on the beach after a gale. These 

 come from deeper water, either where the sand is more 

 firmly compacted than on the shore, or where masses 

 of rock interrupt its continuity, and afford a site for a 

 colony of sea-weeds. One marine plant, however, the 

 only British instance of a flowering plant inhabiting 

 the sea, frequently forms extensive submarine meadows 

 on sandy shores. This is the Grass Wrack (Zostera ma- 

 rina), whose creeping stems, rooting at the joints, ad- 

 mirably fit it for establishing itself on loose sands, and 

 forming the nucleus of a soil in which other plants may 

 grow. Its long, riband-like leaves, of a brilliant green 

 colour and satiny lustre, waving freely in the water, 

 afford shelter and nourishment to a host of marine 

 animals and plants. Great numbers of epiphytic sea- 

 weeds of small size, but many of them of exquisite beauty, 

 may be collected on the leaves of Zostera, which are fre- 

 quented also by numerous Zoophytes, and by the smaller 

 gasteropodous Mollusca. A Zostera-bed. is therefore al- 

 ways worth examining. But it is chiefly when the Zos- 

 tera grows beyond the reach of the tide, and is raised 

 by dragging hooks through it, that it is found so well 

 clothed with Sea-weeds and Zoophytes. Nearer shore it 

 frequently collects muddy particles, which defile all that 

 grows upon it. This plant is collected on many parts of 

 the coast, and even imported in large quantities from 

 the Baltic, being sold under the market name of Alva 

 marina, to the manufacturers of cheap bedding. It is 

 said to form a very tolerable bed, and certainly a cheap 



