CHAPTER XVII 

 THE PACIFIC FIELD 



NSIDE waters are so numerous all along the 

 Atlantic coast that a few short canals would 

 provide an enclosed navigable waterway from 

 Massachusetts Bay nearly to the South Caro- 

 lina line. Some of the Gulf shore is similarly protected 

 by outlying spits and islands. But the Pacific coast, 

 from the entrance to Puget Sound southward to Mexico, 

 is entirely different, being straight, unbroken, and un- 

 protected. There are few enclosed bays or even har- 

 bors on this great stretch of coast, the only extensive 

 ones being Puget Sound, in Washington, and San Fran- 

 cisco Bay, in California. 



The same species of plants and animals are not found 

 in Atlantic and Pacific, but more or less distantly related 

 forms. The class Asteroidea, of zoological classifica- 

 tion, for example, is represented by several species of 

 starfish in one ocean, and by somewhat different kinds 

 in the other. The eastern oyster, Ostrea virginica, is re- 

 placed on the Pacific coast by another species of the same 

 genus known as Ostrea lurida. On the Mexican coast 

 are still other species. 



Ostrea lurida is much smaller than the eastern oyster, 

 and differs from it also in having a light, thin shell, and 

 in being hermaphroditic, a condition in which each in- 

 dividual produces both male and female cells. In the im- 



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