T THE GUDGEON AND TROUTLING MADE STRAIGHT FOR THE WEEDS.]

"What think the caterpillars?" said the hedgehog.

The caterpillars were studying moral invisibility in a hundred different
ways, for insect life is the most highly specialized of all. It was the
lobster-moth-to-be that spoke first. He bent his head backwards until it
touched his tail, folded the knee-joints of his skinny legs, and began--

[Illustration: IT WAS THE LOBSTER-MOTH-TO-BE THAT SPOKE FIRST.]

"It is all bluff," said he, "caterpillars are past-masters of bluff. Look
at the hawkmoths, fat, flabby, bloated things, with curly tails. Most of
them fling their heads back, arch their necks, and play at being snakes.
Some grow eyes upon them, not real eyes, but markings which serve as such,
enough to scare the average chuckle-headed bird. Sometimes they trust to
vein-markings on their bodies, which turn them into casual misshapen
leaves. Sometimes they liken themselves to twigs--"

"That is what we do," cried the loopers. Each branch of the oak had its
loopers, feeding cheerfully, transforming themselves to twigs, and
shamming death in quick succession.

[Illustration: MOST OF THEM FLING THEIR HEADS BACK, ARCH THEIR NECKS, AND
PLAY AT BEING SNAKES.]

"Sometimes," continued the lobster-moth-to-be, "they are, like myself,
really worth eating. Then, mere vulgar imitation bluff is of little avail.
To be a withered leaf is my first line of defence; if the ichneumon
buzzes nearer, I shift my ground and become a spider. I am the only
caterpillar in the country with spider-legs; when they are stretched to
their full length and quivering, they are worse to look at than the real
thing. Should even this fail me, I show the imitation scar on my fourth
body-ring. That usually clinches the matter. The ichneumon fondly imagines
that I am already occupied. So, if I am lucky, I turn at length to dingy
pupa, and thus preserve my race."

[Illustration: NOT REAL EYES BUT MARKINGS WHICH SERVE AS SUCH.]

[Illustration: EACH BRANCH OF THE OAK HAD ITS LOOPERS.]

"Will you hear an amphibian?" said the toad. He came from the centre of a
grass-tuft, and spoke with solemn deliberation. "Not one of you is more
persecuted than I. From time immemorial I have been the loadstone of
credulity, and--I am altogether defenceless. I am never worth eating, for
the shock of capture opens every pore on my skin, drenching me with what
the poets class as venom. So I am usually thrown aside wi