Referee's report by Sidney Frederic Harmer, on a paper 'Observations on the development of ornithorhynchus' by James Thomas Wilson and James Peter Hill Secional Committee: Zoology Recommended for publication in full and without modification in Philosophical Transactions. The entire series of illustrations should be published. Special care should be taken not to loose the detail of the photomicrograph figures. In general the paper is an extremely detailed account of the early development of Ornithorhynchus [platypus]. The more important results are concerned with gastrulation and with the neuromeric segmentation of the latest stage as described and they are checked by references to the development of reptiles and marsupials. Parts of the paper are of controversial nature. The memoir could, in Harmer's opinion, have been written more succinctly but in view of the morphological importance of the Monotremata, and the difficulty in obtaining their embryos, it will be well to allow the author to present their results in their own way. It is obvious the author's have spared no pains to make their account as reliable as possible. [Published in Philosophical Transactions A, 1908]. Endorsed on verso as received 12 February 1906 9 February 1905