PROCESS FOR PRESERVING PEARL-OYSTER FISHERIES. 313 
the hope that they would become inoculated with the pearl-inducing cestode 
or at least to propagate and maintain the growth of oysters on the banks. 
The immediate objects in view were therefore— 
(1) The prevention of the theft of pearls from the rightful owners of the 
oysters. 
(2) A great increase in the yield of valuable pearls from a given number of 
oysters. 
(3) The maintenance of the yield of oysters from the natural beds, if not a 
positive increase therefrom, as against the destruction of the fisheries under 
present methods. 
In actual working the radiographs are brought wet out of the process build- 
ing, wherein all exposure and developments are made in ‘‘dark-room’””’ light, 
and with good light and the wet radiograph practically nothing can escape. It 
is easier to disclose that an oyster contains a pearl than actually to extract the 
pearl. If the process errs, it errs on the side of safety. We find that we set 
apart many oysters as containing seed pearls, which further examination shows 
contain none, but that what was shown in the radiograph was an imperfection 
in the film, an air bubble, a piece of coral outside the shell, etc. With practice, 
even these mistakes can be eliminated, but they are not of such a nature as to 
make us lose or eliminate an oyster which has the possibility of developing a 
valuable pearl. With sufficient and proper help and auxiliary appliances, the 
plant on Ipantivu Island, with its single tube equipment, can radiograph up to 
400 oysters per minute. These thin-shelled, small Ceylon oysters (Margaritifera 
vulgaris) are easy to handle. But we can attain just as much success with the 
fresh-water mussels of the United States and other countries, and with the larger 
Margaritifera maxima peculiar to Australia, Burma,etc. In fact my first experi- 
ments were made on these. We can not, of course, do so many at a time or so 
quickly, as they require a longer time of exposure, but on the other hand, the 
product is of much greater value. My plant on Ipantivu Island has completely 
fulfilled all expectations, and, so far as concerns the possibility of radiographing 
pearl-bearing oysters on a commercial scale in order to disclose the contained 
pearls and without injury in any way to the oysters, has proved my process to 
be a complete success. 
Unfortunately, owing to certain conditions which arose after I came to 
Ceylon and invested my capital, and which have prevented my getting live oys- 
ters, I have up to now been unable to prove the next and equally important 
-stage of my process. However, as to whether pearl oysters known to contain 
seed pearls can be kept under such conditions as will make them continue to 
live and grow and thrive, and the majority of the contained seed pearls likewise 
to increase in size and consequent value, I leave it to the members of the Inter- 
national Fishery Congress to decide. 
