CBTPTOGAMS 



177 



BROWN ALGJE 



428. The Brown Algse (Fig. 291) are almost exclusively 

 salt-water plants. They are in most cases attached. In size 

 they range from microscopic, unicellular forms, through 

 the fine filamentous species (Fig. 291, D), to thalloid 

 forms of immense length. " Of these, 3Iacrocystis fyrifera 



2*11 . Browu AlgtB : .4, the Sea Colander (much reduced) : B, Larainaria (much 

 reduced) ; C, the Gulf W^eed with floats (a) ; 7), Ectocarpus (magni- 

 fied), s being sporangia. 



is noted for its gigantic size : rising obliquely upward to 

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

 tions in the ocean bed, its floating thallus has a length of 

 600 to 900 feet. The stalk below is naked, but at the 

 surface, where it streams out horizontally, it bears man}^ 

 long pendent segments, each provided at the base with a 



OUT. OF EOT. 



12 



