186 JOURNAL, R.A.S. (CEYLON). [VOL. XVI. 



they evidently had to give away when the strain of a current 

 of that velocity was prolonged for a week. I doubt very 

 much their ability to resist even a 3 -knot current for that 

 length of time. 



Young oysters have a much stronger hold than oysters 

 advancing to maturity. The divers often remark when on 

 young oysters that they could not bring up many, as they 

 were holding on fast ; but when they come away easily the 

 divers say they are fit for fishing. 



There is no record of a current similar to that of December, 

 1887, having occurred previously, and I look upon that one 

 as very exceptional, particularly as to its course, which was 

 in a south-easterly direction, 



I am of opinion that it was caused by an unusually large 

 volume of the north-east monsoon ocean current flowing 

 into the Gulf of Mannar, and seeking an outlet by sweeping 

 round the head of the gulf, and down its eastern shore, 

 until it joined the main stream on its course from the coast 

 of Ceylon towards Cape Comorin. It is well known that the 

 current from the Bay of Bengal in November and December 

 runs south along the east coast of Ceylon at the rate of 2 to 

 3 knots an hour. It curves round the south coast, and after 

 rounding Galle takes a north-westerly course past Cape 

 Comorin. Sometimes it follows the west coast of Ceylon to 

 the north of Negombo, and then branches off towards Cape 

 Comorin. A larger volume than usual coming this way 

 would probably advance further up the coast than Negombo, 

 say to Chilaw, and then branch off towards Cape Comorin, 

 and in that case some portion of the stream might, before 

 reaching Cape Comorin, be deflected along the Tuticorin 

 shore and then follow the course I have described. I cannot 

 account for a south-east current on the Cheval Paar in 

 December in any other way. 



There are also unknown enemies of the pearl oyster. For 

 instance, when oysters too young for fishing are found dying 

 off in large numbers, it has not yet been discovered what 

 causes them occasionally to be in that condition. 



