THE HAUNTS OF LIFE 61 



include a stranded whale in the littoral fauna. As we shall 

 see later on, many of the distinctive littoral animals pass 

 through a pelagic phase, but that again is a different matter. 

 Our point at present is the simple one, that there is much 

 in the jetsam which does not belong to the shore. 



Keen Struggle for Existence. It is evident that the 

 shore-area must be characterized by a keen struggle for 

 existence. In the open sea there is practically no limit to 

 the floating room and swimming room, but the shore is 

 narrow and crowded. In a rock pool there is often no 

 vacant niche. There is competition even for foothold. It is 

 important for instance that the limpet which makes little 

 journeys in search of seaweed to nibble should not go too 

 far, else it will not find its way back, and will have lost 

 the spot which its shell has grown to fit. It is curious, too, 

 to see the American slipper-limpet one growing on the 

 top of another to the number of four or five suggestive 

 of the root-idea of a sky-scraper. 



There is abundant food in the shore-area, for there is 

 a great crop of seaweeds to start with, but there is nothing 

 to compare with the pelagic sea-meadows an inexhaustible 

 supply of microscopic Algae extending for square mile after 

 square mile, and for many feet in depth. Thus on the 

 shore there is much more struggle for food competition 

 around the platter. It is lessened by the fact that there 

 is considerable variety in the dietary, some being carnivor- 

 ous, others vegetarian, others feeding on microscopic ani- 

 mals, and others on debris, but one must remember that 

 even the crumbs of organic matter, formed on the shore or 

 brought down by rivers, are always being swept away by 

 the undercurrent to greater depths. The most must be 

 made of them before they are lost. 



