Unpublished paper, 'On the development of the head-muscles of the common fowl (Gallus domesticus) together with some remarks on the head muscles of reptiles' by F H Edgeworth Edgeworth writes: 'A few papers have been published on the early stages of the development of the head-muscles of Gallus and other birds, and on the histological details of the insertion of the mandibular muscles into Meckel's cartilage and the lower jaw; but as yet there has been no description of the formation of all the head-muscles in any one bird which might serve as a basis for a discussion of their morphology. The following paper is a contribution to the subject, based on an investigation of Gallus.' Subject: Zoology Received 5 January 1906. Read 16 February 1906. 1906