424 The Tinnevelly Pearl Batiks. 



the shell altogether, entangled amongst the strands of the 

 byssus. When the pearl banks are under constant supervision, 

 the causes leading to the formation of pearls, as yet im- 

 perfectly understood, will, doubtless, receive close attention. 



It now only remains to describe the plan by which it is 

 hoped that, in future, the Tinnevelly pearl banks will be kept 

 supplied with a sufficient number of well-grown shells to supply 

 a remunerative annual fishery. The idea was suggested by the 

 method adopted with regard to edible oysters on the English 

 and French coasts. The chief external difference between the 

 pearl and edible oyster is, that the former secures itself to 

 rocks and stones by means of a byssus, while the latter merely 

 lies flat on the ground on its convex side ; but there is no 

 reason why the pearl oyster should not thrive on artificial banks 

 as well as the edible oyster. 



In the Colne oyster fishery, the brood (oysters two years 

 old) are dredged up out at sea, and placed on " layings " within 

 the river Colne. These "layings " are about 100 or 150 yards 

 by 80, according to the breadth of the channel, most of them 

 dry at low water, and they are paved with stones, old shells, 

 and any other hard substances, to a depth of a few inches, 

 so as to form a bed for the oysters, which would be choked in 

 soft mud. This material is called culch. In France, M. Coste 

 has adopted a system of placing fascines on the layings, instead 

 of culch, as resting places for the oysters; but the natural 

 advantages of the ground render any artificial method of this 

 kind unnecessary in the Colne. It is very important that the 

 culch should be kept perfectly clean and clear of mud, and, 

 above all, that every mussel-shell should be weeded out. The 

 mussels have a remarkable tendency to collect mud round 

 them in heaps, probably owing to their elongated shape, and 

 if they are allowed to remain on the Iwyings, there is danger 

 of the oysters being choked with mud. The oysters remain on 

 the layings for two years, when they are fit for eating, and 

 during this time there are constant examinations, in order 

 that all dead fish may be removed, and the culch kept clear 

 of mud. In places where the layings are never laid bare by 

 the tide, this is done by means of a dredge, all live fish and 

 culch, being carefully thrown back, while dead fish, soft mud, 

 and mussels are removed. 



There can be little doubt that some s»ch system might be 

 adopted iu rearing pearl oysters, and Dr.Xelaart says that "he 

 sees no reason why pearl oysters should not live and breed in 

 artificial beds, like the edible oysters, and yield a large revenue." 

 Melius ascertained, by his experiments in Ceylon, that the 

 pearl oysters are more tenacious of lifo than any other bivalve 

 with which he is acquainted, and that they can live in brackish 



