Oyster Culture in America 121 



very unfortunately they are not to be had in large quan- 

 tities. 



Large parts of the Gulf oyster field possess an ad- 

 vantage over the Atlantic coast that some day may prove 

 to be very important, in its immense deposits of small 

 si 1 el Is. These could hardly be improved on for the pur- 

 pose of collecting oyster spat. They are hard, but so 

 small that clustering on them would be impossible. At 

 the same time, they are heavy enough to remain unmoved 

 in a strong current. These will be described in another 

 place. 



In certain parts of Long Island Sound, water-worn 

 pebbles or fragments of crushed rock are employed as 

 collectors, or " cultch." Though this material is some- 

 what more expensive than shells, its pieces are so small 

 that oysters cannot cluster on them. It cannot, how- 

 ever, be used on soft bottoms, unless enough of it is em- 

 ployed to act both as pavement and cultch. On hard 

 bottoms, from five to six hundred bushels are spread 

 over an acre — somewhat more than when shells are 

 used. 



Rarely spat is collected over very soft bottoms where 

 the water is shallow. This is accomplished by driving, 

 the bases of saplings into the mud, leaving their branches 

 immersed. Now and then a heavy set is gathered on 

 them. If oysters are allowed to grow where they have 

 attached, they are likely to fall into the mud because of 

 the decay and softening of the bark. For this reason, 

 the brush is usually removed soon after attachment is 

 accomplished. 



It is possible to use many other kinds of material for 

 cultch. Scraps of tin and tin cans, for example, serve 

 the purpose well when they are available, and very sue- 



