26 THE OYSTER. 



great part from the springs of the interior, which, flow- 

 ing through limestone regions, carry some of it away 

 in solution, and this is finally carried down the rivers 

 and into the bay. Some of it is no doubt derived from 

 deposits of rock in the bed of the ocean, and some from 

 the soil along the shores. Now, the geologist will 

 tell you that the limestone rock has all ofitatonetime 

 been part of the bodies of living animals. Limestone 

 is either old reefs of fossil coral, or beds of extinct 

 shells, or the skeletons of other animals and plants 

 which lived in remote ages and stored up the lime 

 from the ocean at a time when it was more abundant 

 than it is now. The oyster gets the greater part of its 

 lime from these sources in this roundabout way, but a 

 very considerable portion is obtained in a much more 

 direct way, by the decomposition of old oyster shells. 



We save up ^^% shells to feed laying hens, but we 

 waste our oyster shells in every possible way, and 

 treat them as if they were of no value. Some are 

 burned for lime, some are used for making roads and 

 wharves, some are used for filling in low land, some 

 are dumped in great piles at convenient spots in the 

 bay, where they sink far down into the mud and are 

 lost. 



I shall show you soon that there is another far more 

 important reason why they should be returned to the 

 beds, but their value as food for the oyster is very 

 great, and should lead us to return them to the beds. 

 On the oyster-beds an old shell is soon honeycombed 

 by boring sponges and other animals, and as soon as 

 the sea-water is thus admitted to its interior, it is 

 rapidly dissolved and diffused. In a few years nothing 



