CETPT0GA3IS 



177 



BROWN ALGJE 



428. The I>ro\vii Algiu (Fig. 291) ure almost oxclnsively 

 salt-water plants. The}' are in most cases attached. In size 

 they range from microscopic, unicellular forms, through 

 the hue fihmieatous species (l^ig- 291, D), to tlialloid 

 forms of immense length. " Of these, llacroci/nt/fi pyrifera 



291. Brown Algre;: ^, the Sea Colander (much reduced) ; 73, Laniinaria (mnoh 

 reduced) ; C, the Gulf Weed with floats (a) ; D, Ectocariius (magni- 

 fied), s being sporangia. 



is noted for its gigantic size : rising obliquely upward to 

 the surface of the water from tlie sloping sides of eleva- 

 tions in the ocean hed, its floating tliallus has a length of 

 600 to 000 feet. The stalk below is naked, but at the 

 surface, where it stri'ams out hoiizuntally, it bears manj' 

 long pendent segments, each provided at the base with a 



OUT. OF EOT. 12 



