4 
filled in by the zoophytes. In these our little 
artizans are busily at work ; and these portions 
of the reef contrast greatly with those main 
portions on which the zoophytes have made their 
operations, where all is decay. Arrived at the 
verge of the outer reef, we are induced to lie 
flat on it, and with our head projecting over it 
we gaze down first with awe and astonish- 
ment into the abyss below us ; and nothing can 
exceed the grandeur of the scene which pre- 
sents itself. The water is perfectly clear and 
transparent, and for several fathoms below the 
observer is a succession of masses of beautiful 
corals, sea plants, and weeds of every variety 
of hue, rising out of a white sandy bottom, 
which shelves more or less abruptly towards 
the ocean, or, not unfrequently, inclines in- 
wardly towards the reef like a mushroom, 
giving one a feeling of insecurity when he 
reflects that it is just possible that the ledge on 
which he is reclining might give way and carry 
him into the depths below. I have frequently, 
when I have seen beautiful and rare shells glit- 
tering amongst the white sand apparently only 
a few feet below me, thought of taking a dive 
after them, but the idea of a shark lurking in 
some concealed crevice under me, would give a 
most decided negative to so rash a proceeding. 
An examination of the reefs, although attended 
with much labour and fatigue, amply repays 
one for the wonders they develop j the 
naturalist may generally return from such 
an excursion laden with treasures. I usually 
carried a chain-hook, such as sailors use for 
handling a chain cable: with this I was enabled 
to turn over large fragments of coral which had 
been detached from the outer reef and driven 
into cavities, around the base of which’beds of 
white sand, or, rather, pulverised coral, had 
accumulated ; in these beds, or adhering to 
the lower portion of the coral thus turned over, 
I have collected many beautiful specimens of 
cones, corals, and other shells, a description of 
which would only serve to lengthen this paper. 
I cannot, however, refrain from remarking 
upon one species, which, from its size, forms no 
insignificant ingredient in the construction of 
the coral islands. I allude to the tridacne, or 
giant clamp shell. Some of these grow to 
enormous dimensions, and are usually seen 
with their valves open frequently a yard in 
diameter, and woe to the unlucky wight who 
introduces his hands, or puts his foot into 
this novel trap, the result of which 
would, inevitably, be loss ot limb — 
such is the muscular power possessed by these 
gigantic oysters, for such they may be consi- 
dered, their flesh being edible. These clamp- 
shells are often found entirely embedded in 
coral — the zoophytes slowly but surely work 
around them, and eventually build them into 
the general mass. We will now suppose our- 
selves back to the corner edge of the reef, 
where the bank, as already stated, slopes to- 
wards the lagoon. Here we find the coral 
teeming with life, and our little friends the 
zoophytes actively engaged in filling in the 
lagoon. 
The appearance of these reefs when the sun 
shines on them is really beautiful, their colour 
vieing with the richest emerald. The reef 
being once raised to a level with the sea, we 
can easily imagine the action of the waves 
causing detached portions of the outer reef to 
accumulate, and afford, in the first instance, a 
shelter for sea-birds, which form their nests ; 
and the matter deposited from the egg-shells 
after hatching their young, the remains of the 
fish with which they feed them, combined with 
their guano, soon renders the calcareous soil 
capable of supporting various kinds of vege- 
tation, the seeds of which are carried by cur- 
rents from the adjoining coasts or islands, and 
deposited on the new formation. This process 
is assisted by visits from migratory birds, 
which again deposit a variety of seeds with 
their dung — particularly those of fruit. A suc- 
cession of vegetation which flourishes and 
decays, not only increases the depth of the soil, 
but rapidly affords means of subsistence to a 
variety of trees. 
Finding that this paper has already exceeded 
what may be considered a reasonable limit, and 
fearing longer to trespass upon your time, I 
would suggest that if the members of this 
society feel interested in the subject, I might 
be permitted at some future time to offer some 
further information relative to that vast line of 
coral formations extending along part of the 
western coast of India, and southward of the 
equinoctial. I would now submit a rough 
diagram having reference to the formation of 
an atoll, and which I think will convey a 
clearer idea of the existing theory as regards 
the formation of coral islands than could 
possibly be given by any written description of 
mine. 
A free and interesting conversation followed, 
on the subject of the paper, so far as it referred 
to the east coast of Australia, in which Messrs. 
Rawnsley, Wight, Diggles, and others took 
part, the two former maintaining that the coast 
was gradually rising, which fact seemed rather 
to militate against a portion of Mr. C. Darwin’s 
theory of coral formations. 
Mr. Coxen will read a paper on the Regent 
Bird at next meeting. 
Printed by G, Wight, “Guardian Office,” Brisbane. 
