Referee's report by Alan Nigel Drury, on a paper 'The histology and self-differentiating capacity of the abnormal cartilage in a new lethal mutation in the rat (Rattus norvegicus)' by Honor Bridget Fell and Hans Grüneberg Sectional committee: Physiology Recommended for publication in Proceedings. The paper is clear and no modifications are needed. [Published in Proceedings of the Royal Society B, 1939]. Endorsed on verso as received 11 January 1939. January 1939