OLIVE -GREEN AND BROWN 

 SEAWEEDS 



THIS subclass contains some of the most remarkable of the 

 seaweeds. It is especially notable for the diversity of its plant 

 forms, which range from filaments to plants which appear to have 

 stems and leaves (Sargassum}. The species vary in size from very 

 small fronds to those of immense size (the Laminariacece). It in- 

 cludes Fucus (the rockweeds), a very conspicuous genus, which 

 furnishes fully three fourths of the vegetable covering of the 

 tidal rdcks in the localities in which it grows. 



ORDER ECTOCARPACEJE 



This order comprises many species of branched, filamentous 

 plants, some of which are of hair-like fineness and form beautiful 

 feathery tufts of brownish or olive-green color. They resemble, 

 except in their tawny color, the green alga Cladopliora. 



The name is derived from Greek words meaning "outside" 

 and " fruit," the spores of the plants being borne on the branches. 



The species are determined by the arrangement of the spores, 

 according as they are in the pod-like branches, in groups, or in 

 cases on stalks. Since these differences are not perceptible to 

 the naked eye, it is impracticable to describe many species, or for 

 the amateur collector to try to separate them. 



GENUS Ectocarpus 



E. littoralis. Filaments fine, in dense tufts, interwoven, six to twelve 

 inches long ; pod linear in the substance of the branches ; color olive- 

 green. This is the most common species of Ectocarpus, and grows abun- 

 dantly everywhere, appearing like large, fine, dull-green plumes. (Plate IX. ) 



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