would fall to the ground, tumble about, and then,
getting up again, head in the opposite direction!

Leon was puzzled,--no wonder. He looked around for a solution of this
queer conduct on the part of the ais. No explanation appeared. At length
he bethought himself of going up to them. Perhaps, when nearer, he might
learn what set them a-dancing.

"Ha!" he ejaculated, struck with some sudden thought. "I know now;
there's a snake at them."

This conjecture--for it was only a conjecture--caused him to stop short.
It might be some venomous snake, thought he. The grass was not long, and
he could have seen a very large snake; but still a small coral snake, or
the little poisonous viper, might have been there. He fancied he saw
something moving; but to get a better view he passed slowly around the
edge of the glade, until he was nearly on the opposite side to that
where he had entered. He still kept at a good distance from the ais, but
as yet discovered no snake.

To his great surprise, the ais now lay stretched along the grass, their
struggles appeared each moment to grow less violent, and their
melancholy cries became weaker and weaker. Their contortions at length
came to an end. A feeble effort to raise themselves alone could be
perceived,--then a spasmodic motion of their long crooked limbs,--their
cries became indistinct; and, after a while, both lay motionless and
silent! Were they dead? Surely so, thought Leon.

He stood gazing at them for some minutes. Not a motion of their bodies
could be perceived. Surely they had no longer lived! But, then, what
could have killed them? There was no snake to be seen; no animal of any
kind except themselves! Had they been taken with some sudden
disease,--some kind of convulsions that had ended fatally? This seemed
the most probable thing, judging from the odd manner in which they had
acted. Maybe they had eaten some sort of plant that had poisoned them!

These conjectures passed rapidly through the mind of Leon. Of course, he
resolved to satisfy himself as to the cause of their death, if dead they
actually were. He began to draw nearer, making his advances with stealth
and caution--as he was still apprehensive about the snake.

After he had made a few paces in a forward direction, he began to
perceive something moving around the bodies of the animals. Snakes? No.
What then? A few paces nearer. See! the whole ground is in motion. The
bodies of the ais, though dead, are covered