  The atmospheric neutrino flavour ratio measured using a 1.52 kton-year
exposure of Soudan 2 is found to be 0.72 +- 0.19 +0.05 -0.07 relative to the
expected value from a Monte Carlo calculation. The possible background of
interactions of neutrons and photons produced in muon interactions in the rock
surrounding the detector has been investigated and is shown not to produce low
values of the ratio.
