the rocks, and gazed over into the sea, where we observed the pale-
green object still distinctly visible, moving its tail slowly to
and fro in the water.

"Most remarkable!" said Jack.

"Exceedingly curious," said I.

"Beats everything!" said Peterkin.

"Now, Jack," he added, "you made such a poor figure in your last
attempt to stick that object, that I would advise you to let me try
it. If it has got a heart at all, I'll engage to send my spear
right through the core of it; if it hasn't got a heart, I'll send
it through the spot where its heart ought to be."

"Fire away, then, my boy," replied Jack with a laugh.

Peterkin immediately took the spear, poised it for a second or two
above his head, then darted it like an arrow into the sea. Down it
went straight into the centre of the green object, passed quite
through it, and came up immediately afterwards, pure and unsullied,
while the mysterious tail moved quietly as before!

"Now," said Peterkin, gravely, "that brute is a heartless monster;
I'll have nothing more to do with it."

"I'm pretty sure now," said Jack, "that it is merely a phosphoric
light; but I must say I'm puzzled at its staying always in that
exact spot."