Referee's report by John Monteath Robertson, on a paper 'A comparative X-ray study of foetal and adult sheep haemoglobins' by John Cowdery Kendrew and Max Ferdinand Perutz Sectional Committee: Physics Recommended for publication in the Philosophical Transactions of the Royal Society, although there may be a special reason for putting it in the Proceedings, referring to an earlier work there. The paper is well-written but long, and it would not be easy to shorten it. [Published in the 'Proceedings of the Royal Society of London'] No received date. 10 March 1948