THE SEA SHORES 



The shores of the sea are bathed by the water from the 

 open ocean, charged with microscopic plants and small crus- 

 taceans, and with such of the creatures feeding on these as are 

 able to support the light of day. But because of the fact that 

 the rocks and stones and mud, and to a lesser degree the sand, 

 offer facilities for attachment, conditions here are entirely 

 different from what they are in the open sea. 



Along the shores an attached plant, as a result of the move- 

 ment of the water about it, has constantly delivered to it a 

 fresh supply of the dissolved substances necessary for its 

 growth, and it is maintained permanently under conditions 

 most suitable for its existence. Hence the enormous develop- 

 ment of the brown, green and red algae, or "sea-weeds." 

 Some of the flowering plants, too, have become adapted to 

 marine conditions, and one of these, the eel-grass, belonging 

 to the pond-weed family, forms extensive beds in suitable 

 localities. 



These plants are important in providing hade and hiding 

 places for the animals found among them, and when alive they 

 are eaten by a few molluscs, like the periwinkle, by a few 

 crustaceans and hsh, mostly under stress of hunger, by some 

 sea-urchins and, where these occur, by sea-cows, manatees and 

 dugongs, by some turtles, and by a single lizard. When they 

 die their leaves or fronds break up and the fragments form 

 the vegetable detritus so very important as the basic food 

 of the marine animals along the shores. 



In the open sea the animals can avoid the dangers attending 

 too violent wave action by simply descending to the quiet 

 depths. Along the shores there is no escape from the constant 

 movement of the water. This incessant turmoil on the shore 



171 



