434 MARINE INVERTEBRATES 



as are the fenced-off acres of upland meadows. The business of 

 the oyster-culturist is to plant the young oysters and watch their 

 development, keeping the beds thinned, that the oysters may 

 not be too crowded for their normal and symmetrical growth, 

 and protecting them from their enemies, of which there are many. 

 The principal enemies of the oyster are the starfish and the pre- 

 daceous mollusks Urosalpinx and Nassa. Whole beds have been 

 known to be destroyed in a single night by the visitations of 

 starfishes, hence a constant watchfulness is required on the part 

 of the oysterman. Policing the oyster-farms is another of 

 his cares, for pirates abound, and a bed may be robbed in the 

 night as easily as an orchard may be despoiled of its fruit. Oys- 

 ter-culture is carried on extensively in Long Island Sound, on the 

 coasts of New Jersey and Virginia, and in the Chesapeake Bay. 

 The oysters from certain localities are esteemed more than others, 

 the flavor of the oyster being very dependent upon the purity 

 of the water and on the organisms upon which it feeds. It has 

 been definitely shown that oysters grown in contaminated waters 

 have been the agents of transmitting disease, notably typhoid 

 fever and cholera. 



Oyster-culture has reached the highest degree of perfection in 

 France, where miles of muddy shores left by the ebb-tide are uti- 

 lized for the purpose. The famous pare at Arcachon, covering 

 ten thousand acres, illustrates the system generally practised. 

 The spat is there collected on tiles coated with cement, piled in 

 layers crosswise, and secured in crates. These tiles are exposed 

 in favorable localities and collect the swimming embryos. The 

 rough cement holding the spat is then chipped off the tiles and 

 placed in wire trays. These ambulances, or caisses ostreophiles, 

 placed between short posts, protect the fry from their ene- 

 mies. At low tide the young oysters are carefully examined 

 and sorted, and at the right age they are removed to open areas. 

 The pare is divided into regular squares by canals of suitable 

 width, some of the squares having banks and gates to retain the 

 water of the receding tide if desired. Each man's pare is sepa- 

 rated from that of his neighbor by canals of greater width, and 

 often by stakes having a few branches on the ends. These pi- 



