GRASS-GREEN SEAWEEDS 



r INHERE can hardly be a more fascinating group of plants 

 1 than this, whether to the strictly scientific botanist or to 

 the more catholic lover of nature. The green algae are among 

 the most widely diffused of plant forms. They grow practically 

 in every place where enough moisture, together with light and 

 air, is to be had. Between tide-marks on almost every coast, 

 floating on the surface of the deep sea, covering damp earth, 

 walls, palings, and tree-trunks, sticking to the surface of leaves 

 iu the moist atmosphere of tropical forests and jungles, and in- 

 habiting almost every river, brook, pond, ditch, or casual pool of 

 rain-water in all quarters of the globe, are members of this 

 ubiquitous group to be found." l 



The grass-green seaweeds are more simple in structure, and 

 therefore are lower in order, than the red or brown algaB. They 

 are among the lowest of all plants, many of them being minute 

 single cells. They abound in fresh as well as in salt water, and 

 in this respect differ from the other groups, the red and the brown 

 algae being almost exclusively marine plants. 



As one approaches the shore, the attention is often attracted 

 by the green mantle which covers everything overflowed by the 

 tides. This consists largely of the confervoid algaa, which are 

 very abundant and are found almost everywhere. They are 

 dense tufts of fine thread-like plants, often matted at the base ; 

 sometimes they are sponge-like, floating masses. 



The Ulvaceae, the plants next higher in order, are the first 

 which assume ribbon- and leaf-like expansions, and usually first 

 engage the attention of the collector. 



1 Kerner. 

 52 



