Referee's report by Allen Thomson, on a paper 'On the arrangement of the muscular fibres in the ventricles of the vertebrate heart, with physiological remarks' by James Bell Pettigrew Recommended for publication in the 'Philosophical Transactions of the Royal Society'. The dissections were on display at the Royal Society when the paper was read, which gave a chance for the referee to inspect them. The diagrams do not coincide exactly with the dissections. Suggests a simplification of the descriptive part by a slight rearrangement of topics covered. The illustrations are too numerous and complicated for inclusion in print. Suggests a smaller number of carefully finished drawing be produced. Suggests a re-wording of the paper to improve clarity. Subject: Physiology [Published in the Philosophical Transactions of the Royal Society, 1864] 1860