Few pearls are found and it not infrequently happens that as many as fifteen to twenty tons of shells are raised without finding a single pearl of value. At this time shells from these fisheries bring from $500 to $750 per ton in the New York market. Helmets have been used to some extent throughout the Pacific for a number of years, but many were crude affairs, carelessly managed and the loss of life was as great as by naked-diving. The training of the natives to the use of the more modern appliances will however engender confidence and the probability is that dress-diving will become general in the south seas wherever the industry is organized. As a rule the largest oysters and pearls, where there is a calcareous foundation for the bed, are taken from the deeper waters, and it is probable that as modern appliances are more generally used by the larger organizations now taking hold of the industry, the fisheries will be extended with good results in many localities to waters beyond the shallows now fished. More systematic methods will prevent waste and the destruction of the beds. The English Colonial governments of India are doing much in this direction. By keeping experts upon the ground, they have learned how to fish without destroying the beds, and to fish when it is possible for the oysters to contain pearls. Strict supervision and protection of the beds result in more frequent fishings and greater returns to both the government and the fishermen. This example is being followed, and pearl fisheries are gradually coming either under governmental supervision or into the hands of concessionaires, whose large investment makes the preservation of the beds a business necessity, whether they fish mainly for pearls or shells. The best pearls and the largest number are found usually in mature shells which are distorted; it has been stated as a possibility, that in the future some of the new rays will be used in fisheries where the pearl is the main object of the fisher, to ascertain if the oyster contains any before destroying it. M. Dubois of Lyons has experimented with Roentgen rays for that purpose. As the fish is enormously prolific it is more probable however that effort will be directed instead toward the preservation of the mollusk from the enemies and accidents which are occasionally greater than its productiveness. One of the greatest dangers in Indian waters to a bed of young oysters is a little mollusk known locally in Ceylon as suran (Modiola). These cluster in masses on the sea bottom and spreading over the surface of the coral, crowd out the delicate young of oysters recently deposited. The Japanese fisheries suffer from the occasional infection of the waters by a weed, dinoflagellata gonyaulax. It accumulates in immense quantities, causing a wide discoloration of the sea water and is very destructive to an oyster-bed. It is called the red current or red tide. So far no preventive or remedy has been found.