Referee's report by Nevill Francis Mott, on a paper 'The cascade theory of electronic showers' by Lev Davydovitch Landau and G Rumer Sectional Committee: Physics Recommended for publication in the 'Proceedings of the Royal Society of London'. Finds the paper obscure in places, suggests the paper be returned to the authors for revision. Suggests clearly defining some of the terms in the equations. Refers to work of Homi Jehangir Bhabha and Walter Heinrich Heitler, to whose results the author should compare their own. Suggests the use of English requires revision, which he is willing to do if necessary. [Published in the 'Proceedings of the Royal Society of London'] Endorsed on verso as received 17 December 1937. [December 1937]