er mill is grist. She's as bad--and worse--than the
elm-beetle."

By this time the cooking molasses smelled so good, the cabin fire roared
so pleasantly, and the smell of the flapjacks Adam was frying was so
appetizing, that the children had quite forgotten the storm outside, and
were having one of the jolliest frolics of their lives--one they never
forgot.

"Tell us something more, sir," urged Jack, "about the beetles."

"There is one comical fellow who makes me think of Peter. In the books
it is called a click-beetle, but it is also called a skip-jack because
of the somersaults it can turn. On the under side of its thorax is a
spine resting on the edge of a hole. This funny beetle, by pushing the
spine down over the hole and then letting it go, throws itself up in the
air with a sharp click."

"Oh, I know them," called Hope, "for I have seen them doing it, but I
never knew how they did it!"

"And now," said Master All-Wise, very soberly, "after I tell you that
the children of the click-beetle are called wire-worms, and that they
eat and kill the roots of plants, I want to tell you about a beetle no
one of you has ever seen--a most extraordinary beetle."

[Illustration:
_A._ Lady-beetle.
_B._ Burying-beetle.
_C._ Oil-beetle.]

All were attention at once.

"Many years ago there lived away out in California a little, round,
brownish, striped beetle, which crawled about and ate heartily of a
plant called the sand-bur. One day one of the family happened to wander
up to a nice, juicy potato plant. After eating its fill it probably
looked up some of its brothers and sisters, and told them about these
good plants growing in the fields. With one accord they left the
sand-burs and began to eat the potato plant. Farther and farther they
wandered, until thousands of them reached the eastern part of our
country, eating the potato plants wherever they found them on the way.
Now, these beetles are to be seen everywhere in our country, spoiling
crop after crop."

By this time Jack's eager face was smiling, and he was looking
questioningly at Ben Gile.

"What kind of a beetle do you suppose it was?" asked the old man.

Nobody knew. At last Jack ventured, "Was it a potato-bug, sir?"

"Yes."

"Oh, of course!" shouted the children. "Why didn't we think of that?
But you said we had never seen it."

"So I did," said the guide, "and I don't believe there is one child here
who has ever carefully watched the potato-bug. A