s a name applied to the flesh of certain sea
slugs or sea worms found in the Indian seas. Of this substance great
quantities are gathered annually. In the water the animals resemble huge
cucumbers, and they are therefore sometimes called "sea-cucumbers." They
are found clinging to the rocks below low-water mark, and are from one
to four feet in length. Their food consists of microscopic shell-fish
which live upon the coral rocks.

[Illustration: The Great Barrier Reef of Australia, the most remarkable
animal structure in the world]

The trepang exported from this section requires considerable care in
preparation. After being gathered from the rocks they are cleaned,
boiled, and partly dried in the air; then they are smoked with mangrove
wood until dry and hard. The best class of trepang is packed in tin
cases to keep it perfectly dry, as moisture ruins it. The product is
marketed chiefly at Hongkong, where it is used in making the gelatinous
soups for which the Chinese are so famous.

The pearl-shell fisheries yield products of considerable value. The
average depth from which the mother-of-pearl shell is gathered is seven
or eight fathoms. Twenty fathoms represents the greatest depth in which
divers, even in their diving suits, can work, so great is the pressure
of the water upon them.

The fishery is carried on chiefly for securing the shells, the finding
of pearls being of secondary importance, since only about one shell in a
thousand contains a pearl of much value. The shells themselves bring in
the market from three hundred to eight hundred dollars per ton according
to quality and size, and are used chiefly for making buttons and small
ornaments.

The Cairn Cross Islands, a little coral group midway between Cape
Grenville and Cape York, are especially interesting as the home and
nesting-place of the Torres Strait pigeons. These large white pigeons
are highly esteemed for the table. They gather at the islands during the
month of October and remain until the end of March. The nests are
usually built in the forked branches of the mangrove trees that form
extensive thickets along the coast. Each nest contains two white eggs.

The Australian jungle-fowl or scrub-hen also frequents these islands as
well as the mainland. The nests of these birds are large and unique.
They consist of huge mounds of dead leaves, grass, sticks, and soft
earth piled together by the adult birds in shaded and sequestered
places. The mound