Has two-dimensional superfluidity been observed? There has been a continuing controversy as to whether or not this interesting phenomenon, predicted theoretically for ideal two-dimensional systems, has been seen in real liquid helium-4 films. Dash has argued persuasively (Phys. Rev. Lett. 41, 1178; 1978.' that it has not; and that the experiments which had apparently demonstrated the effect were misinterpreted. Some new measurements now reported by Webster, Webster and Chester of the University of California at Los Angeles (Phys. Rev. Left. 42, 243; 1979) seem, however, to have tilted the balance of the evidence back in the affirmative direction once more, in favour of the original interpretation.