COASTLINES 



a tiny fraction of the coastline populations. Darwin 

 realized that he could occupy several lifetimes in the 

 study of earthworms. One would need as many to study 

 the anatomy, habits and life-cycle of any single coastal 

 species, selected at random from among the tens of 

 thousands of distinct kinds which inhabit the world's 

 sea- fringes. 



The tides of the sea, conspiring with the world's 

 rivers, continually deposit living animals and organic 

 matter upon the ocean shores, but such living and 

 (apparently) dead material is not left anywhere where it 

 is deposited. The word "apparently" is a necessary 

 qualification, for even the waste matter and debris 

 deposited by waves on the shores, and by land and ocean 

 rivers in their tidal interplay, swarm with microscopic 

 life. 



We must therefore begin our survey of the world's 

 coasts with this basic conception : that they are not 

 merely areas of rock formation, or stretches of sand and 

 pebble, subject to breaking and receding rollers, but 

 worlds within worlds of living creatures, and that the 

 waters which beat against them and flow inward and 

 outward across them are inhabited — every cubic inch of 

 them — by untold millions of microscopic life-forms. 



Corals in infinite variety, shells in almost inconceivable 

 profusion, crustaceans of every imaginable kind, and 

 enormous multitudes offish, are here along the coastlines 

 for our selective examination. Those that we consider 

 will serve to illustrate the magic, beauty and wonder- 

 ment of the multitudinous shapes which rest and move 

 along the coasts, and float or swim in the waters that 

 cover the ocean shelves. 



There are three main divisions of the living creatures 

 of the sea, if they are classified according to their life- 

 habits. The term nekton comprises the swimmers — fishes 

 of all kinds, squids, whales, and so on. Plankton may be 

 described as including those free-swimming creatures 



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