PROCEEDINGS OF SECTION D. 545 
Torres Straits, lying west from Bado or Mulgrave Island, and 
familiarly known to the fishermen as the “Old ground.” Some 
forty vessels, luggers of ten or eleven tons burden, were then 
engaged in shelling operations in the area traversed by the 
Albatross. The majority of these were boarded, the manner of 
working observed, materials collected, and much practical infor- 
mation elicited from the divers. It was found in this connection 
that all the medium-sized pearl-shells, up to a diameter of seven 
or eight inches, were attached, in a similar manner as the young 
ones already described, by a strong byssus, or anchoring cable, to 
a supporting fulcrum, which consisted chiefly of the frag- 
ments of coral and shell, of which the sea bottom in this district 
is composed. The shells of larger size, nine or ten inches in 
diameter and of considerable weight, 5 or 6 lbs., were in all 
examples I examined devoid of a byssus, and rested simply on 
their ocean bed. A similar condition was observed, also, of 
several shells of the same size I personally collected at extreme 
low tide, on the Warrior and other outlying coral reefs. Such 
adult shells evidently require no cable to keep them anchored in 
the tideway, their own weight insuring their stability, which 
is in most instances further secured by the luxuriant growth upon 
their exposed upper shells, usually the right valve, of heavy 
madrepores and other corals, such as the well-known cup coral, 
Turbinaria peltata, and innumerable varieties of sponges, shells, 
sea-weeds, and other organic growths. Under such a combined 
weight it would be altogether impossible for the animal to move, 
and the question of their migratory habits previously suggested 
may, in face of the practical evidence now adduced, be most 
distinctly answered in the negative. Many young shells, corres- 
ponding in every essential point with those referred to as having 
been obtained from the bottom of the Star of Peace, were also 
found adhering to the adult individuals. These were saved alive, 
in company with a series of matured specimens, to form the 
subject of further investigation. 
One of the most important objects of the expedition was to 
ascertain by direct experiment if it was possible to bring the 
pearl-shells in alive from the outer fishing-grounds, and to relay 
and cultivate them in the shallower inshore waters. The evidence 
hitherto adduced was not favourable to this proposed scheme, 
the majority of the witnesses interrogated maintaining that the 
shells would not survive removal from their native habitat, and 
that all attempts previously made to transport the shell had 
failed. In order to thoroughly test the matter, several distinct 
methods were now resorted to. Some fifty examples, varying in 
dimension from five or six to as much as ten inches in diameter, 
were placed at my disposal by the different boats. The majority 
of these specimens were immersed in two tubs of sea water on 
board the Adbatross, the water being run off and renewed in them 
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