AS Dr. Bashford remarks in his introductory note to the report of the Cancer Research Fund,1 the solution of the problem of the cause of malignant disease in man is really the logical destination and centre towards which all channels of cancer research must converge, rather than the starting point thereof. The zoological distribution of cancer has therefore formed one of the first lines of inquiry to be undertaken by the Cancer Research Fund, founded about two years ago, for investigating this dire disease. By the willing cooperation of many workers, a most interesting series of tumours has been obtained from the various domestic animals, from the mouse and hen, and from three species of fish, proving that malignant disease is not confined to man. The malignant growths of man seem to be incapable of transmission to animals, but a malignant new growth from one animal may occasionally be transmitted to another individual of the same species. This has been carried out by Jensen, of Copenhagen, and by Borrel, of Paris. Through the kind collaboration of Prof. Jensen, a specimen of epitheliomatous tumour of the mouse was obtained and successfully transplanted into mice, but not into other animals, thus confirming Jensen's results.