SEA-WEEDS. 131 



is almost useless as a characteristic, giving us 

 scarcely any idea of the nature or properties of 

 the plant, and varying under circumstances of soil 

 or culture. Thus we see the wild hyacinth trem- 

 bling in the spring wood, and we call it the 

 blue-bell; but we step into the next copsewood, 

 and there we find our favourite woodland flower 

 arrayed in purest white. The "brown or purple 

 heath" sometimes greets us unexpectedly with 

 snowy bells, and white blossoms sometimes sur- 

 prise us on the root where we expect to find the 

 pink flowers of the Robert-leaved cranesbill. 



The fructification of the Alga is usually so 

 minute, as to need the assistance of a microscope 

 to detect it. Little wart-like excrescences, termed 

 capsules, lie on the surface of the frond ; or spots, 

 called granules, are imbedded in its substance, or 

 scattered on its surface. Some plants bear both 

 these kinds of fruit, in which case the marine 

 botanist terms the capsules the primary, and the 

 granules the secondary fruit; though both cap- 

 sules and granules contain seeds (sporules), which 

 can produce a new plant. The grass-green sea- 

 weeds are remarkable for having seeds which 

 possess a singular power of locomotion, in some of 

 the plants of the series appearing to be voluntary, 

 so that naturalists have not yet decided as to 

 whether they may not be endowed with animal 

 motion. 



The very commonest of all our red sea-weeds is 

 the Hair Flag, or Landscape weed (Plocamium coc- 

 cineum). So frequent, indeed, is this plant, that 

 every one who visits the sea-side must have seen 

 it, and it is seldom omitted in those drawings of 

 marine weeds which accompany pictures of groups 



K2 



