And there are enemies innumerable. The terrible sharks, prowling about near the bottom, prove a source of perpetual uneasiness, and in the aggregate many fishermen are eaten by these bloodthirsty tigers of the sea. There are horrible conflicts with devil-fish equaling that in Hugo’s “Toilers of the Sea.” The saw-fish is also a source of danger, particularly in the Arabian Gulf, and instances are reported in which divers have been cut in two by these animals, which sometimes attain a length of twelve or fifteen feet, and possess a saw five feet long and three inches broad, armed on each edge with teeth two inches in length. Another menacing peril is the giant clam (_Tridacna gigas_), a monster bivalve, whose shell measures two or three feet in diameter, and is firmly anchored to the bottom. This mollusk occurs on many of the Asiatic pearling grounds. Lying with the scalloped edges a foot or more apart, a foot or a hand of the diver may be accidentally inserted. When such a fate befalls a fisherman, the only escape is for him to amputate the member immediately. Once in a while on the pearling shores a native may be found who has been maimed in this manner, but usually the unfortunate man does not escape with his life. [Illustration: CAP OF STATE, FROM LOOTING OF SUMMER PALACE, PEKIN, IN 1860 Now in South Kensington Museum ] THE PEARL FISHERIES OF CHINA, JAPAN, SIBERIA, ETC. Do churls Know the worth of Orient pearls? Give the gem which dims the moon To the noblest or to none. EMERSON, _Friendship_. It appears from ancient Chinese literature, noted in the first chapter of this book, that pearl fisheries have existed in the rivers of China for several thousand years. The Chinese also derived pearls from the sea, and especially from the coast of the province of Che-kiang. Little is known of the early fisheries, but the fragmentary literature contains so many allusions to pearls as to lead us to believe that they were of considerable extent and importance. It is related that about 200 B.C., a pearl dealer at Shao-hing, an ancient city between Hang-chau and Ning-po, on the shore of Hang-chau Bay, furnished to the empress a pearl one inch in diameter, for which he received five hundred pieces of silver; and to an envious princess the same dealer sold a “four-inch pearl.” A hundred years later, the reigning emperor sent an agent to the coast to purchase “moon pearls,” the largest of which were two thirds of an inch in diameter.