even under the best conditions the diver not infrequently becomes semi-paralyzed and disqualified in a few years. Notwithstanding that the work is performed by men in vigorous health, nearly every year there are from ten to twenty-five deaths in the Queensland fleet alone;[260] three fourths of these are due to paralysis, and most of the remaining result from suffocation, owing largely to inexperience in use of gear. From five to ten years is the usual length of a man’s diving career, although in the fleet may be found men who have been diving for twenty-five years or more. On the vessels manned by Japanese, commonly several members of the crew are competent divers and take a turn at the work, although only one license is secured. Such a vessel carries only one head-piece, but two otherwise complete suits, the helmet fitting either, so that as soon as one exhausted diver comes up to rest, a successor is ready to have the helmet screwed to his body-dress and descend without delay, thus saving about half an hour in the changing. The nude divers in the Australian pearl fisheries are mostly Malays and Australian aborigines. They work from dinghys operated from a vessel, each dinghy carrying six or eight divers, usually with a white man as overseer. The man in charge sculls against the tide to keep the boat stationary over the ground, and all the fishermen of a particular dinghy descend together for greater safety from sharks, and to cover the ground systematically. On rising, each diver swims to the boat, throws his catch over the gunwale, and climbs in to rest for a few minutes. Sometimes two or possibly even three oysters may be brought up at a single descent, but a diver is doing well if he brings up one oyster in ten descents. The average daily catch of each man is probably two or three oysters, but a fisherman has been known to bring up fifty in one day. On some vessels, those who fall behind in the catch are punished by extra duty aboard ship. The pearling industry has had a marked effect on the industrial and social condition of the natives of the Australian coast and the adjacent islands. Many of these natives now have boats of their own, and others seek employment on other vessels. Law and order and decent respect for property have arisen, with schools and churches. The result is all the more remarkable when it is considered that scarcely more than a generation has passed since labor among the men was unknown, the women doing all the work necessary to meet their scanty requirements.