148 EDIBLE BRITISH MOLLUSCA. 



holds it securely. When a sufficient number of bam- 

 boos have been prepared, they are planted very closely 

 together on the mud flats, much in the same way as a 

 gardener plants cuttings. At the end of about a month, 

 the spat, which had attached itself to them when planted 

 out, has developed into small oysters. The bamboos 

 are then taken up and transplanted about six inches 

 apart. In four or five months the bamboos are almost 

 hid by the oysters which cluster round them, and which 

 are now collected and sold.* The shells of the oyster 

 and murex were used by the Romans as tooth-powder, 

 and oyster-shells are now used as manure. The 

 Chinese use the shells, when ground down, in certain 

 skin diseases; and the valves of Ostrea talienwanensis, 

 and of other species of oysters, are calcined wntil quite 

 white, pulverized, and then mixed with the juice of 

 certain plants, as a dressing for ulcers.f In the crab 

 traps in China, which are made of bamboo in the shape 

 of a truncated cone, the bait is placed in the middle of 

 the basket, and an oyster is generally used for that 

 purpose. 



Juan Francisco de San Antonio, in his ' Chronicos 

 de los Rel. Descalzos de S. Francisco/ &c, 1738, men- 

 tions the use of great oyster-shells for " holy water," 

 and speaks of one known to be ninety years old, by the 

 layers of its shell. But I fancy he must mean the shell 

 of the Tridacna gigas, as we know it is used for that 

 purpose; and in the church of St. Sulpice, in Paris, 

 are two of these shells resting upon rock-work in 

 marble, by Pigalle; they were given to Francis I. by 



* * China : Imperial Maritime Customs,' &c. 



f ' Essai sur la Pharmacie et la Mature Medicale des Cliinois,' par 

 J. 0. Debeaux. 



