362 THE ZOOLOGIST. 



ensure a steady flow of water between the Mare Piccolo and the 

 Mare Grande, and somewhat cleanse this cesspool. Taken at 

 63 J° F., the average density of the water is 1023, rising to 

 1025 near the railway. The depth of the sea varies from 26 to 

 39 ft. 



Here some thirty-two proprietors possess Oyster farms, 

 varying in size from 2000 to 3000 square yards. The Tarantine 

 Oyster farm (sciaia) is formed thus : into the bottom of the sea 

 four or five rows of stout piles, either single stakes (piombi) or 

 pairs (fuerci), are driven. The stakes are set about 15 ft. apart, 

 and project 3 to 6 ft. above water level. The form of this stake- 

 work or palisade is usually rectangular, 325 by 98 ft., giving a 

 moderate-sized farm. At the ordinary half-tide mark the stakes 

 are bound together with a thick grass rope (libano) extending 

 round the whole palisade. Every pair of opposite stakes also is 

 tied together ; the parallel ropes so formed are called ventie, 

 and these with the libano divide up the whole farm into a number 

 of square spaces (camere), of which the sides are 15 ft. Lastly, 

 across these spaces, from corner to corner, diagonal ropes (cro- 

 ciere) are stretched. The purpose of this network of horizontal 

 ropes will be presently explained. 



The method of collecting the young Oysters is a special 

 feature of this system. In the natural course of events the 

 brood, after issuing from the mother, swim freely in the sea for 

 some two or three days. After this period they attach themselves 

 to any solid substance in their way, and develop as Oysters. 

 Failing to meet suitable materials, such as rocks, stones, wood, 

 &c, they sink to the bottom, and, if material for attachment is 

 there not forthcoming, they perish. Artificial collection therefore 

 consists in providing the spat with substances to which they can 

 cling; such substances are called collectors. 



The typical Italian collector is a bundle or fascine of dry 

 branches. Chestnut, oak, plane-tree, juniper, furze are used ? 

 but the lentisk (Pistacia lentiscus) is preferred. During the 

 months of March and April, so as to be ready for the spatting 

 season, the boughs are dried and beaten free of leaves. Then 

 they are tied up in bundles with a piece of grass rope. About 

 one yard of this rope is left free to be used for attaching the 

 bundle to the mooring-rope or steso. The fascines are next 

 dipped into a thick solution of lime mixed with a little hydraulic 



