Scotch pearl-fishing was revived in 1860 and some fine ones were sold to Queen Victoria, the Empress of the French, the Duchess of Hamilton and others. Pearl-mussels have been found in Lochs Rannoch, Tay, Lubnaig and Earn, also in the Don, the Leith and other streams. Some are found in the Welsh streams, and the river Bann in Ireland was noted for the fine pearls found in it. Many years ago there was a pearl fishery at Omagh in the north of Ireland. An old writer claims that Cæsar obtained pearls of such bigness in Britain that he tried the weight of them by his hand. The fishers wade for them in shallow pools, or thrust sticks between the open valves, or drag branches over them, for as soon as anything enters between the two shells they close upon it at once. The mussels are found generally set up in the sand of the river-bed with the open side, if the current is very strong, turned away from it. The custom of the peasantry is to fish for them in the autumn after harvest. Pearl-mussels are found also in Saxony, Bavaria, Bohemia, Mesopotamia, Lapland, Canada, Labrador, the Hawaiian Island Oahu, Japan (especially the anodonta japonica), China, the United States and Italy, in the Gwaai and Shangani rivers of Southern Rhodesia, South Africa. Nowhere are they found however in such quantities or in so many varieties as in the United States. The number taken from the streams here of late years has been so great that the shells have largely displaced the marine Egyptian and have affected the demand for the better qualities of South Sea mother-of-pearl. The pearls found in them also have been of such quality and quantity that they now have an important place among the jewels of the world. Old records and the contents of Indian mounds show that the unio was taken from the rivers by the aborigines for the pearls they sometimes contained; but no wide interest in this possible wealth of the rivers appears to have developed among their white successors until the finding in 1857 of a large pearl weighing ninety-three grains at Notch Brook near Paterson, N. J. It was afterwards sold to the Empress Eugénie of France for $2500. This became noised abroad and immediately multitudes began to search for pearls. Mussels were gathered and destroyed by the million, few pearls being found. The excitement subsided as the searchers learned how few got adequate reward for their time and labor. They soon began to realize that the finding of a pearl of value is usually preceded by the opening of hundreds or thousands of shells containing none, and that in the aggregate, the shells thrown away were worth more than the few pearls found.