390 
THE TROPICAL AGRICULTURIST, 
[Dec. 1, .:00. 
•cultivating pearl oysters were made by Mr, W 
Saville Kent, F.L.S., late Commissioner of Fisheries 
to the Government of Queensland and Western 
Australia ; but the very short period over wliich his 
investigations extended, and the limited facilities 
which he enjoyed for the conduct of his research, 
rendered it impossible for him to achieve results of 
any value. He however showed that artificial fer- 
tilisation and incubation are quite possible, though 
the questions of conservation and protection from 
enemies still remain to be dealt with.* 
THK PEARL FISHERY OF JAPAN. 
In the Bay of Agu, in the Province of Shima, 
Japan, an extensive pearl fishery exists. The pearl 
oyster of this region (M. Martensit) appears to 
be the most northerly situated of the pearl-bearing 
species of Bleleagrina, and it lives under con- 
ditions which more nearly resemble those which ob- 
tain on the oyster banks of Europe— where the true 
oyster (Ostrea edulis) is cultivated— than those 
which surround its own congeners in tropical seas. 
The Japanese pearl oyster lives in quite shallow 
water, and is left exposed upon the banks at low 
tide. This condition of things would seem to pre- 
sent special facilities for artificial cultivation ; but 
unfortunately, on this very account large numbers 
of the shells perish of the cold in winter. Professor 
Mitsukuri, of the Imperial University, Tokyo, has 
inaugurated an elaborate system of cultivation, 
which gives promise of good results. One of the 
prin3ipal features of the scheme is the collection of 
the " spat " in shallow water, and its transference 
to comparatively deep water— 6 to 7 fathoms— 
where the temperature is more equable. Here the 
young oysters are constantly watched and protec- 
ted against the attacks of predacious foes. I hope 
to be able to obtain further particulars of this in- 
teresting experiment as the work proceeds. At 
present fuller information is not available. 
Artificial cultivation after the Chinese method 
has also been attempted in Japan ; but, so far, 
onlv hemispherical pearls, whose bulbs are attached 
to the shell, have been produced. Japanese pearls 
are not commonly seen in the markets of London 
and Paris, probably because there is always a de- 
mand for these at home. 
THE PEARL FISHERIES OF CALIFORNIA AND 
PANAMA. 
In the time of the Jesuit Missionaries the Central 
American pearl fisheries were actively carried on, 
and produced great wealth to those engaged in the 
industry. But they afterwards fell into decay, and 
for many years 'the banks were thought to 
have been exhausted. More recently, however, 
the industry has been revived— chiefly owing to 
the introduction of modern diving apparatus, which 
has proved of great utility. 
Mr. Townsend, of the U.S.A. Fish Commission, 
says: " It is not unlikely that the adoption of 
the submarine engineer's suit by the pearl fishers 
of La Paz must have been the step which led to 
the continuance of the pearl fishing industry, for 
the search tor shells can now bo pursued into 
deeper waters than in the days of the naked divers, 
the best of whom could not descend a dozen 
fathoms. Half that is rather more than a practi- 
cal working depth." And again in the same re- 
port Mr Townsend says "Whatever of romance 
has 'hitherto enshrouded the naked diver for 
pearis in the sea, he is now practically a subma- 
• Sea Appendix to the Beport of the Governmsnt 
Resident of Thursday Island for 1898, by S, Pace, 
F.Z.S. 
rine labourer who uses all the modern diving pa- 
raphernalia available- No longer plunging for 
sixty secor.ds into the sunlit green water that 
covers a coi-al bank, he puts on a rubber suit with 
glass-fronted helmet, and, suitably weighted with 
lead, descends for hours to gather pearl oysters, 
which are hoisted in a wire basket by his com- 
panions in the boat above, who also supply him 
through a rubber tube with the air he breathes." * 
M fiynhriata. is the pearl oyster of this region, 
but M mai garitifera is also fished here as else- 
where in the Pacific. Here again, mother-of-pearl 
shell is the principal object of the search, its value 
being sufficient to pay the expense of the fishing, 
leaving any pearls which niaj be obtained a clear 
gain. In America also, as in An^^tralia, the banks 
are rented ©ut for fixed periods to different pearl 
ing traders. 
In the Pacific the oysters are usually opened 
with a knife. This, if properly performed, is said 
to be the best plan, for pearls are considered liable 
to become discoloured if the animal is allowed to 
decompose before the shell is opened. 
THE PEARL FISHERIES OF THE GULF OF MANNAR. 
The principal fishery in this region is that con 
ducted on the eastern side of the Gulf, in tlie 
neighbourhood of Aripo, Ceylon — the pear! banks 
on the Indian coast having now almost ceased to 
be remunerative. 
At the Conference Meeting of the Colonial and 
Indian Exhibition in 1886, Sir James Longden 
(formerly Governor of the Island) remarked that 
the pearl fishery of Ceylon was " one of the most 
ancient — peihapsthe most ancient industry of the 
world ; that it was carried on today as it had been 
for two thousand to three thousand years ; and 
that it owed little or nothing to modern civiliza- 
tion in the manner of getting from the depths of 
the sea that wonderful beautiful product of Na- 
ture, — the pearl, -f 
The Ceylon fishery, besides being entirely carried 
on by unprotected native divers, is further dis- 
tinguished from those which we have just been 
considering in being the only fishery in the Tropics 
where pearls alone are sought for, irrespective of 
the shells, the nacreous lining of the valves of the 
Gulf of Mannar oyster (M fucata) being of little or 
no commercial value. J 
It will not be necessary for me to enter into 
details here regarding the methods employed in 
the conduct of the Ceylon fishery. They have 
already be°n fully described by Capt. Steuart, Sir 
Emerson Tennent, Mr. Vane, Mr. Edgar Thurs- 
ton, and, quite recently, by Sir William Twynani 
in his very complete and elaborate report just 
published. § Let it suffice to say that the indus- 
try is now a Government monopoly, carried on 
* Bulletin, U S Fish Commission, vol. IX, 1889, pp. 
91-94. 
t Proc. Roy. Col., Institute, 1886. 
J The mother-of-pearl oyster (J/ margaritijera) alao 
occurs, though very rarely, in the Gulf of Mannar. 
See ThurstOD, " Pearl and Chaok Fisheries of the 
Gulf o£ Mannar," 1894. 
§ (1) Tennent, " Nat. Hist, of Ceylon," n. 373 ; (2) 
Capt. Stenart, " Account of the Pearl Fisheries,'' 
I8i3; (3) Vane, '■ Pearl Fisheries of Cevlon," RAS 
Journal, vol. X., 1887 ; (4) Thurston, " " Pearl and 
Chank Fisheries of the Gulf of Mannar" 1894 ; (5) 
Twynam, " Report on Ceylon Pearl Fisheries," 1900. 
See also the many valuable " Inspection Reports" 
by Capt. Donnan, Inspector of the Pearl Banks, 
for the last thirty-seven years. 
