iE 
SCIENCE AND INDUSTRY. 
goods. It grows in thick clusters, and is gathered with rakes and 
dredges. The animal is torn from the shell and thrown in masses into 
barrels to rot. After putrefaction has softened the decayed mass, the 
pearls it contained are sieved out. 
Less profitable than pearling, but requiring less skill and capital, 
is the béche-de-mer industry. In 1913, the Australian crop was worth 
£30,000. The trepang, or béche-de-mer, is a soft slug, which as an 
article of food would generally be considered to be of repulsive appear- 
ance. The shape is that of an enormous cucumber. It can contract 
and expand, is covered with rough-looking, but soft, warts, and is 
mottled with various colours—red, brown, orange, or purple. The 
head end puts out a whorl of tufted feelers, which procure food by 
sweeping together sand and microscopic organisms, and thrusting the 
mass into its mouth. Some kinds have the unpleasant habit of voiding 
their viscera when handled, thus earning the name of “ cotton-spinners.” 
CORAL REEF AT LOW TIDE. 
About twenty different sorts have been observed in Queensland, but 
of these only those which have a firm flesh are esteemed of commercial 
value. The choicest varieties are known in the trade as the Black-fish, 
Teat-fish, Surf Red-fish, and Red Prickly-fish. 
It is curious that young specimens are never seen; the béche-de-mer 
appear to spend their earlier life in deep water, and to ascend to the 
level of low tide only when full grown. 
The fishing is often conducted by a fleet, of which the smaller vessels 
forage for supplies and a larger one deals with the harvest. Coloured 
labour is usually employed in collecting. The natives gather the fish 
by hand, wading over the reefs at low water or diving in the deeper 
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