37 



wealth which may be developed by proper legislation, 

 administration, and cultivation of the oyster-beds in N. S. 

 Wales. 



Recent experiments tend to prove that the Rock-Oyster 

 of our shores (Nos. lO, 28, 40, 6y), which is left dry by every 

 tide, is only a variety of the Drift- Oyster ; and spat taken 

 from the rocks at low tides, when laid in beds always 

 covered by the sea, are said to thrive well ; and although 

 Oysters may thrive on natural beds oi mud and sand, when- 

 ever these beds are over-dredged the animals become 

 diseased by the infiltration of mud into the shells. Steamer 

 traffic over the shallow water-beds of the Hunter River, 

 formerly so prolific, has in many cases either deteriorated 

 or completely destroyed them (see examples of this in 

 specimens No. 62^). The black mud stirred up by steamer 

 traffic, and brought down by the tides or " freshes " in the 

 river, has infiltrated into the shell ; the animal, unable to 

 get rid of it, has deposited a layer of nacre over it time 

 after time, until the shell has become formed of thin layers 

 of mud and nacre, and the animal becomes exhausted, 

 diseased, and dies. That natural Oyster-beds can and are, 

 in fact, being destroyed daily by over-dredging, and by 

 traffic when situated in shallow waters, in other countries as 

 well as in Australia, must be patent to any one who has 

 taken the trouble personally to examine into the subject. 

 It is also clear, from the numerous specimens exhibited 

 from our waters, that the depth up to 10 or 15 feet is not 

 material, although the best Oysters are obtained from the 

 shallowest beds, and are grown on a rough shelly, gravelly, 

 or stony bottom. The most highly prized in New South 

 Wales are those from the rocks or beds where the fresh and 

 salt water mingles at certain seasons of the year ; for in- 

 stance, at the estuaries of the river and vicinity of fresh- 



