M. Cuvier lately read a short paper to the French academy on the species
of fish called _pogonias_, in which he particularly adverted to the
noise by which they make themselves heard, even under water. However
difficult the explanation of this phenomenon, there can be no doubt of
its existence; the evidence of it adduced by M. Cuvier being perfectly
satisfactory. The silurus, a large and ravenous fish, which abounds in
the Danube, gives daily proof of it.