lagoon are dead. But why are they dead? Without doubt the living
shells have a very different background set for imitation. But why
are these so different? We are only on the threshold of the
mysteries.

Either beach, I have said, abounds with life. On the sea-side and
in certain atolls this profusion of vitality is even shocking: the
rock under foot is mined with it. I have broken off--notably in
Funafuti and Arorai--great lumps of ancient weathered rock that
rang under my blows like iron, and the fracture has been full of
pendent worms as long as my hand, as thick as a child's finger, of
a slightly pinkish white, and set as close as three or even four to
the square inch. Even in the lagoon, where certain shell-fish seem
to sicken, others (it is notorious) prosper exceedingly and make
the riches of these islands. Fish, too, abound; the lagoon is a
closed fish-pond, such as might rejoice the fancy of an abbot;
sharks swarm there, and chiefly round the passages, to feast upon
this plenty, and you would suppose that man had only to prepare his
angle. Alas! it is not so. Of these painted fish that came in
hordes about the entering Casco, some bore poisonous spines, and
others were poisonous if eaten. The stranger must refrain, or take
his chance of painful and dangerous sickness. The native, on his
own isle, is a safe guide; transplant him to the next, and he is
helpless as yourself. For it is a question both of time and place.
A fish caught in a lagoon may be deadly; the same fish caught the
same day at sea, and only a few hundred yards without the passage,
will be wholesome eating: in a neighbouring isle perhaps the case
will be reversed; and perhaps a fortnight later you shall be able
to eat of them indifferently from within and from without.
According to the natives, these bewildering vicissitudes are ruled