Unpublished paper, 'On the respiratory organs of the common leech (hirudo officinalis, linn.) and their connections with the circulatory system' by George Newport Newport shares his observations on the physiology of the common leech. Includes tabulated experimental results relating to leech lung capacity at different temperatures. Subject: Zoology / Entomology Received 5 June 1833. Communicated by P M [Peter Mark] Roget. Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 3 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'On the respiratory organs of the common leech (hirudo officinalis, linn.), and their connexions with the circulatory system'. June 1833