Generally the nuclei appear to be the bodies or eggs of minute parasites—distoma, filaria, bucephalus, etc., and they vary in different localities according to the animal life of the neighborhood. In the still parts of the river Elster, where water-mites (Limnochares anodontœ) were abundant, Kuchenmeister found that the mollusks contained more pearls. METHODS OF FISHING The beds of the marine shell-fish from which pearls are taken lie always under water. Unlike others which are sometimes left exposed by the tides, to be gathered by man without difficulty, the pearl oyster is never left uncovered by the sea. It is found usually on shoals some distance from shore, sometimes but five to seven feet from the surface; more frequently fifteen to forty feet deep, and often one hundred to one hundred and twenty-five and even one hundred and fifty feet deep. Everywhere, then, man's quest for pearls is confronted by the heaving, restless waters of the sea, for the greater part of the year rough and turbulent, frequently lashed to furious racing by tropic tempests but through which he must in any case go to get them. In a few places where the beds lie in shallow inlets and sheltered bays they can be dredged, but almost universally the oysters are gathered by divers. During the greater part of the year, when storms rage, diving is very dangerous if not quite impossible; but when the song of the sea is hushed to low crooning, and the gentle roll of the waves does no more than playfully slap the boats in passing, then in the seas where men dive for pearls they gather to the harvest of gems. There are two ways of diving—naked, and with dress. The former is the common method throughout the Orient and is practised to-day after the same manner that it was in the days of the Pharaohs and the Cæsars, for the primitive method survives with few variations wherever eastern people control the fisheries. In the fishing season one sees now in the Red Sea and the Persian Gulf and about Ceylon, the same scenes as they were enacted there before Rome was a city, or France a nation, or the Macedonians overran Egypt. Naked divers, diving into fifteen to forty feet of water, use few aids. They grease their bodies, put greased cotton in the ears and a forked stick, or tortoise-shell clip, upon the nostrils to compress them, hang a wide-mouthed wicker basket or net at the waist, and they are ready. There are several methods of naked diving: head-first from a spring-board attached to the side of the boat, as the Malabar coast Hindus and some of the Egyptians do; swimming to the bottom, as practised in the deep waters of the South Sea; and dropping to the oyster bed with a stone. The latter is the most common way in Indian, Egyptian, and Arabian waters, especially where the banks lie in forty to fifty feet of water.