The Lower Plants 59 



the seaweeds par excellence. Of these two groups 

 the Phaeophyceae are almost exclusively marine, 

 while the red algae have a number of fresh- water 

 representatives. 



The Brown Algae. Very different from the small 

 and delicate green algae are the great coarse brown 

 kelps so common along the rocky coasts of the cooler 

 seas. The rocks of the northern New England shore 

 exposed by the tide, are covered with a thick drapery 

 of the common rock-weed, or bladder kelp, and in 

 the deeper water are groves of the big Laminarias, 

 " devil's aprons " in the vernacular. With these are 

 many species, some delicate little plants, but more 

 of them stout and leathery in texture, and all dis- 

 tinguished from the green algae by the presence of 

 brown or yellow pigments which give them their 

 characteristic olive or leathery brown color. Much 

 the same types occur on the western European 

 coasts, but it is in the Pacific that these remarkable 

 plants reach their greatest development. The visitor 

 to the Pacific Coast, from Alaska to Middle Cali- 

 fornia, is at once struck by the extraordinary variety 

 and gigantic size of some of the common kelps, 

 which attain a length hardly rivaled by any land 

 plants, and make these great seaweeds the giants 

 of their class. 



Giant Kelps. Compared with these giants of the 

 Pacific, the largest of the Atlantic kelps are mere 

 pigmies. Two of the Pacific kelps, Nereocystis and 

 Macrocystis, especially merit the popular name of 



