436 ANNUAL KEPOET SMITHSONIAN INSTITUTION, 1913. 



been placed beyond the mantle cavity near the visceral hump. I have 

 succeeded in raising abalone culture pearls in 133 days. These pearls, 

 however, are thin layers of nacre, formed over a horny basis, which 

 is the first material to be secreted. In the natural process of con- 

 tinued deposition they increase in thickness and solidity, and conse- 

 quently in value. One produced in a green abalone in seven months 

 shows good form and luster. My average time for drilling a hole in 

 the abalone shell, inserting the form, and wiring it in place with the 

 numbered metal tag is eight minutes. This working time might be 

 decreased by an expert laborer doing nothing else, so that the busi- 

 ness of raising pearls would be of interest and profit. Mr. C. B. 

 Linton has succeeded in producing similar culture pearls by drilling 

 a hole through the shell center, pushing in a round ball made from 

 shell, and filling the outside end of the hole with beeswax and cement. 



Based upon the fact that each ton of abalone shells represents a 

 certain value of manufactured jewelry and novelties, it is possible to 

 estimate the value of the abalone industry. Shells of the black aba- 

 lone are sorted into two classes. Each ton of those with fine, pearly 

 centers will make novelties and jewelry worth, at retail, $4,000. The 

 class known as button shells, with plain mother-of-pearl surface, rep- 

 resents a final value of $1,000, and the shells of the green abalone 

 $3,000. For the fiscal year ending in July, 1912, the following ship- 

 ments were made from Long Beach and represent the given valuations 

 in manufactured products : Thirteen tons of pearl-center black aba- 

 lone shells, $53,000; 40 tons of button black abalone shells, $40,000; 

 14 tons of dried abalone meats, at $200 a ton, $2,800; a total of 

 $95,800. The shipping statistics are not complete for the other Cali- 

 fornia ports, but it is demonstrable that the abalone industry may be 

 developed into one of great value. 



Much has been said recently in the newspapers concerning the 

 threatened extermination of the abalone. That this is a real danger 

 and not an idle theory is apparent to anyone familiar with the facts. 

 For instance, near Avalon, Santa Catalina Island, not more than 20 

 years ago the green and corrugated abalones were so thick that they 

 rested upon one another four or five deep all over the rocks. After 

 much searching in this locality during the last year I was unable to 

 find a single specimen. The shells brought up by the divers of the 

 glass-bottomed boats, and eagerly bought by the tourists, have been 

 placed in position previously by the enterprising management. Great 

 shell heaps on San Clemente, San Nicholas, and other islands prove 

 the abundance of abalones during the centuries of Indian occupation. 

 Some of the red shells found are unusually large, measuring from 

 20 to 30 inches in circumference. Necklaces of large abalone pearls 

 have been found with the remains of Indians. If only well pre- 

 served, some of these pearls at present would be worth as much 

 as $500. 



