ATTENTION has been directed to persistent questions of interpretation in quantum physics by the recent exchange of views1 on the subject between Dr. H. V. Stopes-Roe and Prof. A. Lande. To Prof. Lande's picture2 of the particle as permanently localized phenomenon, influenced through action-at-a-distance by the extended structure of a measuring instrument, Dr. Stopes-Roe understandably objects that a necessarily detailed and ‘suitable interpretation of the collective action of the apparatus’ has not been provided. Prof. Lande's failure to furnish such an interpretation is equally understandable, since any interpretational superstructure in physics that lacks roots in the underlying mathematical formalism (cf. the luminiferous ether) tends sooner or later to be viewed as excess ideological ballast.