ied Carol Crawford, answering the question for
Willowby. "That is nothing more than they have done for centuries."

"Do you mean migratory movements?" asked the biologist, Rastell. "Rats
have always migrated."

"I mean nothing of the kind," protested Crawford. "I mean their sudden
appearance in a town or a building, their remaining there for a short
time and then their sudden disappearance. The folklore and fairy tales
are full of that sort of thing."

"That is why I asked you to come to this conference, Mr. Crawford,"
explained Willowby. "There is something peculiar happening in New York
at the present time, and it has to do with rats and their actions. In
some way rats of New York seem to be under the control of a set of
racketeers who are able to force them to enter any building they select.
The rats come and go suddenly. It is all over in a little while, but
when they are in the building, they do a lot of damage."

Mr. Crawford interrupted him.

"I doubt if you use the right word, when you say the rats were forced to
enter the building. Perhaps you mean that the rats were by some means
placed in such a psychic condition that they wanted to enter the
building."

"That brings the matter into my field of research," insisted Professor
Wilson. "I doubt the fact that they were forced, but if they wanted to,
why that brings up all kinds of interesting questions."

"That is what I am after, gentlemen. I simply want to present the
problem to you and have you solve it. I personally am satisfied with one
thing. These rats are no different than the rats of five thousand years
ago. They are just like the rats of classic Greece and imperial Rome.
Maybe Mr. Crawford will tell us how they acted."

The antiquarian fairly beamed as he started to ride his favorite
hobby-horse.

"Of course, the story everyone thinks of is the one concerning the Piper
of Hamelin. It was in the year 1284. The rats were thick, and the Piper
agreed to lead them out of the town for a certain sum. He played a pipe,
no doubt some kind of flute, and the rats followed him. When the people
refused to pay, he returned on the 26th of June, the feast of Saints
John and Paul, and again played on the pipe. This time the children, one
hundred and thirty in number, followed him into a cave and were lost.
The date is well documented. A number of historians believe that it
actually occurred, and on the gate of the town is the statement.

"'_CENTUM TER DEN