The Mighty Deep 



which is lovely and valuable, no thanks whatever 

 are due to the producer. 



An oyster makes pearls simply for its own 

 convenience. As in the case of other bivalves, 

 if any foreign substance happens to get inside the 

 shell, and cannot be pushed out, it is straightway 

 covered over, and thereby rendered harmless. 

 Sometimes the intruder is a grain of sand, 

 sometimes a parasite. Oftener yet, it is an 

 oyster-egg which has proved a failure. In any 

 event, the oyster promptly clothes it in that 

 beautiful material — pearl — which it secretes by 

 nature, and because it cannot do otherwise. 



We know well enough the ordinary size of 

 ** edible " oysters. The pearl-forming relatives 

 are often much larger, having shells from eight 

 to twelve inches in diameter. 



One does not commonly associate the idea 

 of Mind with a Limpet. Yet it appears that 

 even limpets are not without the organ of 

 locality. 



Human beings, brilliant in other respects, are 

 sometimes woefully deficient in this quality. But 

 a limpet knows what he is about as to the 

 geography of his own locality. He chooses 

 his resting-place with care, much preferring a 

 smooth rock-surface to one that is broken or 



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