434 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



such causes is more than counterbalanced by the abundant supply of , 

 wholesome food given them, and by the decrease in infanticide and 

 other savage practices to which they were formerly addicted. 



Methods of fishing. — The method pursued in pearl fishing is for a num- 

 ber of vessels to start out together and fish on the same ground. Each 

 vessel carries supplies to last a fortnight. When in about 8 fathoms of 

 water, if the tide is slack, the diver will jump overboard. His boots 

 are heavily weighted with lead, so as to hasten his descent. Upon reach- 

 ing the bottom he walks leisurely along until he comes to a patch of 

 shells ; then he signals to the boat to cast anchor. He carries with him 

 a sack or bag to hold the shells, and as soon as it is filled it is lifted 

 up, emptied out, and sent down to him again, he being able to remain 

 under water several hours at a time. Som.e divers remain down from 

 9 o'clock in the morning until 5 o'clock in the afternoon. 



The pearl-oysters lie on the ground, with the shells i^artly open, and 

 great care is required in handling them, for if touched in the wrong 

 way they will close upon the hand like a vise. Accidents of this kind 

 not infrequently happen to inexperienced divers, who are- obliged to 

 signal those above to lift them up and remove the pearl-oyster from 

 their hands. 



The monsoons which blow in the strait from May until the end of 

 September are often so severe that boats have to lay up for as much 

 as ten days at a time. The average catch for each boat is from 1 to 1^ 

 tons of shells per month. Unlike the fisheries in Ceylon and the Persian 

 Gulf, there is little or no diflBculty in collecting the shells, for they either 

 lie loose on the ground or are only partially buried in the mud or sand. 



The tislieries off the coast of West Australia, and especially at Shark 

 Bay, produce the true pearl-oyster {Avicula margaritifera). For a long- 

 time this shell was supposed to be valueless on account of its thin and 

 fragile structure, but now there is a great demand for it both in America 

 and in Europe. It is especially prized by the French and German 

 artists for fine inlaid cabinet work. 



The young or chicken shell is the best, and commands the highest 

 price. When the pearl-oyster is five or six years ol d the shells become 

 blistered and wormy, and it is said that the oyster dies about the age 

 of seven years. The divers in fishing make no effort to select any par- 

 ticular shell, but take every one that they can get, even the dead shells 

 which have the least A^alue of any, on account of various blemishes, rot. 

 tenness, lack of luster, &c. Pure- white silver-edged shells are the best. 



The oysters in the West Australia fisheries are generally obtained by 

 passing an iron dredge over the banks, but divers are also employed. 

 Pearl-oysters are gregarious in their habits, and whenever one is met 

 with it is almost certain that numbers of others will be found in the im. 

 mediate neighborhood. 



Divers are expert swimmers, and they go down to a depth of 4 or 

 5 fathoms, where it is said some of them can remain two minutes. The 



