668 
THE TROPICAL AGRICULTURIST. [April *, 1888. 
in the telegram which reached Government and 
was communicated to the press. It looks as if Mr. 
Twynam shared the belief, so strongly expressed 
and tenaciously adhered to by a correspondent of 
our own, of the large influence on the peail banks 
of the rivers, especially the Arivi-aru, vhieh pour 
iheir waters (sometimes in great abundance and 
with great force) into the Bay of Silavatturai, in 
which, about ten to twelve miles from the shore 
the two most productive banks — the Cheval and 
Modaragam — are situated. We have indicated our 
own leaning to the belief that the volume of fresh 
water carrying organic as well as inorganic matter 
into the sea, must have some effect on the oj sters, 
probably in aiding the growth of the alga 1 which 
constitute the chief food of the animal which 
secretes the precious nacre. But the writer of this 
article never admitted the idea that even the 
heaviest flood of fresh water which ever rushed 
down the Arivi-aru into the sea could have force 
enough adversely to affect or sweep away the oys- 
ters on beds ten miles away from the mouth of 
the stream. Had excess of fresh water minghng 
with the salt proved fatal to the oysters, the very 
argument on which Captain Donnan rejects the 
skate theory would apply, — the young oysters would 
not have survived, but perished even more readily 
than those of mature age. Formidable as the rays 
are, it i3 quite incredible that they could in two 
months destroy 156 millions of oysters and " leave 
not a wrack behind. ' Equally inadequate as a 
cause would be any small and isolated ease of 
"poaching," which could occur without the dis- 
covery of the illicit proceeding. Fishing of chanks 
is, for good rsasons, forbidden over the area of 
the pearl banks, and we have never heard of a 
case of poaching better authenticated than that in 
Miss Mai tineau'3 sensational story, in which she 
represented a native woman adorned with jewels 
accompanying her husband on a midnight said to 
the preserves so cruelly "monopolized" by a ty- 
rannical Government! We have not the slightest 
doubt, in view of the report made to Captain 
Donnan of the prolonged existence of a 4 knot 
current sweeping across the banks with their average 
depth of seven fathoms, and especially in view of 
the crucial and conclusive experiments he institut- 
ed, that the sudden and terrible destruction of the 
beds of oysters which promised so well for three 
successive fisheries was due to the Gulf current, 
— due, if not to its absolute force, yet to the per- 
sistent, long-continued action of that force. The 
mechanical effect of the current, operating for a' 
lengthened period affords a quite sufficient cause 
for the separation of the oysters from their anchor- 
ing cables and their r;moval into the very deep 
water which is found in close contiguity to the 
banks, and well might the poet say that 
"Full many a gem of purest ray serene, 
The dark unfathomed caves of ocean bear," 
if the millions of pearls swept into those caves 
survive attrition, which is doubtful. No pearls 
have ever been found in sand collected on the banks 
brought to the surface and searched. 7'he oysters 
cannot survive in deep water — their voluntary 
change of locality by means of the "foot" with 
which they are supplied being limited to localities 
in depths of not more than ten fathoms, and their 
movements are generally towards the portions 
nearest the surface of the fragments of rock and 
coral to which they generally adhere — although 
they often fix themselves on other shells and ad- 
here to each other in clusters. No doubt Captain 
Donnan has rightly judged, that, beside the pro- 
bably greater strmgth of their more recently forme 
cables, the less resisting surface offered to th 
currents accounts for the young oysters being 
spared while the older and larger shells were suc- 
cessively torn away. The survival of bo many 
young oysters is a consolatory element in the face 
of the great loss incurred, and since Captain 
Donnan wrote, more than a fortnight ago now, 
the actual results of the fishery, in number of 
oysters fished and especially in prices obtained, 
have gone far to justify the hope, that, although 
we cannot look the promised series of fisheries, 
which former estimates justified, yet the present 
fishery will bring an appreciable and very wel- 
come addition to the island treasury, — not pro- 
bably below the sum cautiouslv calculated on, 
R400,000. Some of the prices paid, up to R109 
per 1,000, will go far to compensate for the en- 
ormous tribute claimed from the pearl banks by 
the Gulf currents and the profound depths into 
which they sweep all the objects they capture. 
Capt. Donnan says nothing of the influence on the 
pearl-bearing animals of mud or sand carried by 
the current which will henceforward be memorable, 
but it is only natural to suppose that enough of 
either or both must have been present, to be a 
factor of some importance in the destruction of 
the bivalves. It may be true, as Capt. Donnan is 
represented as having said, that he has never 
found deposits of mud on the pearl banks. That 
would not prove that some of the enormous quan- 
tities of mud which are beiog deposited in the 
lagoons on our north-western shores and on the 
coast of Southern India has not been swept on to 
the pearl banks and off them again, doing mis- 
chief in the process. Currents alone are quite 
sufficient to account for the frequent destruction 
of the pearl oysters, but it seems only probable 
that the currents carry an appreciable quantity of 
sand and mud across the banks and beyond them. 
(Official Report.) 
From the Inspector of Pearl Banks to the Hon. the 
Colonial Secretary. 
SUBJECT— " FAILURE OF OYSTERS ON 
CHEVAL PAR." 
Barque "Sultan Iskander," Silvatturai, 19th Feb. 1888. 
Sir,— I have the honor to report my return to this 
place yesterday from the pearl banks. 
2. I went out from here on the morning of the 
6th iust. to lift samples of oysters from the Cheval 
Par, and to buoy off the various parts of the bank 
for fishing ; but to my deep regret I found the whole 
bank almost clean swept of oysters. 
3. I was employed seven days in carefully going 
over the bank, four days on the eas^ side and three 
days on the west side, with the following result. On 
the north part of east side I found only about 
459,000 oysters, on centre part of east side only about 
4,948,000 oysters, on south part of east side only 
about 2,438,000 oysters, and on the whole of the 
west side only about 493,000 oysters ; making in all 
about 8,330,000 oysters left on the whole Cheval out 
of 164,429,684 oysters estimated to be on it in Nov. 
last, thus showing a loss of about 156 millions of 
oysters in two months. 
4. On the 13th inst., when I had ascertained the 
state of the Cheval, I sent the "Active" to Mannar 
with a telegram to the Government Agent, Jaffna, 
reporting the very serious loss of oysters, which he 
no doubt duly communicated to Government. 
5. As regards the cause of the disappearance of 
the oysters, I found as an unmistakable fact that 
the oysters had been forcibly removed from the 
bank, The divers employed in its examination 
brought up from the bottom pieces of rock and 
large pinna shells on which there were numer- 
ous oyster byssus attached, quite fresh looking, 
showing that the oysters had only recently vacated 
their positions. In one spot on the centre part of 
