his back legs do not
touch each other_. Now it is a law of friction that you cannot have
friction between two back legs if the back legs are not touching; in
other words the grasshopper does not rub his back legs together to
produce stridulation, or, to put it quite shortly, he does not rub his
back legs together _at all_. I hope I have made this point quite clear.
If not, a more detailed treatment will be found in the Paper which I
read to the Royal Society in 1912.

Nevertheless I have always felt that there was something fishy about the
grasshopper's back legs. I mean, why _should_ he wave his back legs
about when he is stridulating? My own theory is that it is purely due to
the nervous excitement produced by the act of singing. The same
phenomenon can be observed in many singers and public speakers. I do not
think myself that we need seek for a more elaborate hypothesis. _The
Encyclopaedia Britannica_, of course, says that "the stridulation or song
in the _Acridiidae_ is produced by friction of the hind legs against
portions of the wings or wing-covers," but that is just the sort of
statement which the scientific man thinks he can pass off on the public
with impunity. Considering that stridulation takes place about every ten
seconds, I calculate that the grasshopper must require a new set of
wings every ten days. It would be more in keeping with the traditions of
our public life if the scientific man simply confessed that he was
baffled by this problem of the grasshopper's back legs. Yet, as I have
said, if a public speaker may fidget with his back legs while he is
stridulating, why not a public grasshopper? The more I see of science
the more it strikes me as one large mystification.

But I ought to have mentioned that "the _Acridiidae_ have the auditory
organs on the first abdominal segment," while "the _Locustidae_ have the
auditory organ on the _tibia_ of the first leg." In other words one kind
of grasshopper hears with its stomach and the other kind listens with
its leg. When a scientific man has committed himself to that kind of
statement he would hardly have qualms about a little invention like the
back-legs legend.

With this scientific preliminary we now come to the really intriguing
part of our subject, and that is the place of the grasshopper in modern
politics. And the first question is, Why did Mr. Lloyd George call
Lord Northcliffe a grasshopper? I think it was in a speech about
Russia that Mr. Lloyd