204 THE NATURALIST IN AUSTRALIA. 



to a considerable extent through the destruction of immature shell has been checked 

 in Queensland waters by the enactment of an Act of Parliament framed on the 

 recommendation of the writer, prohibiting the taking of pearl-oysters for the market of 

 less than certain judiciously prescribed dimensions. Greater hope for the future, however, 

 undoubtedly lies in cultivation, and towards the practical demonstration that such 

 operations were, though hitherto unaccomplished, perfectly feasible, the writer devoted 

 some time and attention in both Queensland and Western Australia. 



Full particulars regarding the modtis operandi pursued, and the results arrived 

 at in Queensland, being recorded in the author's " Great Barrier Reef" volume, those 

 data will not be recapitulated in detail. It will suffice in the present connection to 

 relate that the shell was brought in from the outer grounds and laid down in natural 

 lagoons in the Coral reefs of Thursday Island, and that it both throve and multiplied 

 under such conditions. The greatest difficulty connected with these operations 

 was found to be the transport of the living pearl shells, which, unlike ordinary 

 oysters, were found to be exceedingly impatient of removal from their native 

 element. It is absolutely necessary, in fact, that they shall be immersed in pure and 

 frequently changed sea water throughout the voyage. As the result of the success 

 attending the Thursday Island experiments, certain of the Torres Straits fleet owners 

 have carried out similar operations on a practical scale, one of these, due facilities 

 being now provided, leasing a large area from the Government between Friday and 

 Prince of Wales Islands for the purpose. A photograph of a portion of the area of 

 the Coral Eeef at Thursday Island, which was the scene of the writer's first success- 

 ful experiments, is reproduced in the upper portion of Plate XXXV. The four corner 

 posts of one of the cultivation frames in which the shells were for safety's sake 

 deposited are clearly seen projecting above the surface of the nearer coral pool. 

 At high tide the entire area of this reef is covered by from two to three fathoms 

 of water, over which there then rushes a deep current of mill-stream-like strength 

 and velocity. 



The Archipelago of Islands in Torres Straits undoubtedly presents exceptional 

 facilities for the inauguration of Mother-of-Pearl shell cultivation. Not only on account 

 of the innumerable sheltered reefs and bays that are there eligible for the purpose, 

 but with regard to the fact that this extreme Northern district lies outside the range 

 of the devastating hurricanes which during the North- West monsoon are liable to 

 visit the more southern tropical zone, and which might cause incalculable damage 

 to Pearl-shell beds laid down in shallow waters. 



