"Why isn't the species exterminated?" asked another frog angrily.

Then the toad near Bobby's ear spoke timidly: "I think you are a little
unjust, Professor. I have known boys who were comparatively harmless."

"It is true there may be a few, Mrs. Bufo," said the professor with
great politeness, "but as a class they may be fairly set down as of very
doubtful value. Speak up, Tadpole, and say if I have made any false
statements so far."

Bobby fairly shouted in his eagerness to be heard.

"We do work," he said. "We have to go to school every day."

"What a help that must be to your parents and to the world at large!"
said the frog with sarcasm. "I am surprised that we never see the
results of such hard labour. Do you know how useful even our smallest
tadpoles are? Without them this pond would be no longer beautiful, but
foul and ill-smelling. As for what we do when we are grown up, modesty
forbids me to praise the frogs, but you know what a toad is worth to
mankind?"

"No," said Bobby. "About two cents, I guess." Bobby didn't intend to be
rude. He thought this a liberal valuation.

"Twenty dollars a year, as estimated by the Department of Agriculture!"
cried the frog triumphantly. "What do you think of that?"

"I should like to know why," said Bobby, looking as if he thought
Professor Rana was making fun of him.

"What are the greatest enemies of mankind?" asked the professor, peering
over his goggles at poor Bobby.

"Tigers," said Bobby, promptly; "or wolves."

"Wrong," said the lecturer. "Insects. Insects destroy property on this
continent to the amount of over four hundred million dollars annually.
Insects destroy the crops upon which man depends for his food. Going to
school hasn't made you very wise, has it? Well, the toads are insect
destroyers. That's their business. If the State only knew enough to make
use of them, millions of dollars might be saved every year. Does it seem
to you that the human animal is so clever as it might be, when it allows
such numbers of toads to be destroyed?"

"It's a shame!" chimed in a voice from the front seats. "We keep out of
the way as much as we can; we eat every kind of troublesome worm and
insect,--the cutworm, canker-worm, tent caterpillar, army-worm,
rose-beetle, and the common house-fly; we ask for no wages or food or
care,--and what do we get in return? Not even protection and common
kindness. If we had places where we could live in safety, who could tell
the