e. go

certain weight of tumour or of a certain quantity of tumour emulsion, for tumour 32, 0·02 gram or 0·025 c.c. a tumour of a certain weight, e. g. 15 grams to 2 grams developed in 10 days, or for tumour 27 only 06 to 0.75 gram, and after an interval of six weeks. These statements imply rapid growth and slow growth respectively, and permit of other investigators judging for themselves in the light of their own experience. Further, the size of the initial dose largely determines the size and weight the resulting tumour will reach in a given time. Its size may vary directly or inversely with the dose, according to differences between different tumours, and between the cells of one and the same tumour at different times. Therefore, when the initial dose is unknown or not stated, no judgment as to the rate of increase is possible.

The report is illustrated by drawings and photographs of the appearances described. The drawings have been made by Mr. Richard Muir, of the Pathology Department, University of Edinburgh, or in the laboratory by Mr. J. R. Ford, of the firm of Shiells & Ford. The microphotographs have been made by Mr. Richard Muir and Mr. W. Imboden, F.R.M.S. The coloured plates have been prepared from drawings made by Mr. Thornton Shiells.

Special recognition is due to the publishers, Messrs. Taylor & Francis, and Mr. Whitehouse of that firm, for the expeditious and accurate manner in which the letterpress and figures have been prepared for publication. The attention they have devoted to the preparation of the report has largely contributed to its appearance at the present time.

A bibliography of all the communications made from the laboratory is appended, the papers being arranged in chronological order.

It has seemed desirable to add an index, in order that the scattered references to the same subject may be made more easily accessible to those interested in particular topics.

Three of the papers in this report are reprinted from the Proceedings of the Royal Society by permission of the Council, to whom the thanks of the Executive Committee are due.

I desire to place on record the zeal with which my colleagues have worked in harmony, in sharing monotonous routine, and in conducting special investigations often overlapping one another. To Mr. Hall I desire to make acknowledgement for valuable assistance in the general supervision of the laboratory service and the care of animals, and to Mr. Miller and Mr. Chapman for much careful histological and other work.

With the completion of this Report all the points raised in the provisional scheme of inquiry drawn up for the Executive Committee in October 1902 and given as an appendix, have been submitted to investigation. The important investigations made by workers elsewhere and also by my colleagues in the laboratory since that date, have naturally had much influence on the conduction of the work. I desire to thank the Members of the Executive Committee and of the various Sub-Committees for the constant encouragement which they have given to the Staff.

June 30th, 1908.

E. F. BASHFORD.

THE ETHNOLOGICAL DISTRIBUTION

OF CANCER.

By E. F. BASHFORD, M.D.

IMPORTANT CORRIGENDA.

Page 2.-19 lines from top: for Sandwich Islands read Fiji Islands.

250

153.-In lines 1, 3, and 14 from top: for fig. 6 read fig. 4.

268.-Fig. 4, at second needle: for A read A'.

395.-In fifth column of Table: blank space in fourth line should read figure "5."

and in divergent races of mankind in accordance with a uniform plan, and over a period of time sufficient to provide adequate evidence of the occurrence of the disease, or, to yield an explanation for its real or

B

apparent rarity. Unfortunately these ends have not been attained after five years' investigation, notwithstanding the whole-hearted support the Foreign, India and Colonial Offices have sought from their representatives abroad, and in most instances have obtained. Nevertheless, much information has been collected, of value in controlling the direction of experimental work and supplementing its results, as well as bearing upon various pre-suppositions as to the pathology of cancer.

The assertion has often been made that cancer is a disease peculiar to Europeans and their offspring, and, when occurring in the natives of other parts of the globe, is due either to communication of the disease from them, on the supposition that cancer is infectious, or due to an acquired tendency to developmental anomalies in consequence of the noxious influences of European civilisation.

The supposition that cancer is an infectious disease has received no support during our ethnological studies. As is well known, the introduction of an infective disease among aboriginal populations by Europeans, has frequently given rise to its most wide-spread and epidemic occurrence in an aggravated and fatal form, ase. g., measles, which more than decimated the inhabitants of the Sandwich Islands, or, to take an infective disease of different category, syphilis which has followed in the wake of Europeans with most disastrous consequences in other regions.

The supposition of communication of the disease has been invoked, for example, to explain the frequency of records of malignant new growths among the negroes of America, and their infrequency in Africa. Our investigations have revealed no indication of endemic foci or of epidemic occurrence of malignant new growths in savage races, nor has it been possible to establish any relation between the frequency with which cancer is recorded in aboriginal races and the degree of exposure to contact with Europeans. Cancer, i. e. Carcinoma and Sarcoma have been discovered in regions where the degree of contact. with Europeans is still at its minimum. Isolated cases of cancer have been reported in Europeans living in parts remote from civilisation as well as in savages. The latter facts show, on the one hand, that Europeans may be attacked by cancer although living for many years under a strange environment, and, on the other hand, that the natives were not naturally exempt, but offered as it were a favourable soil for the disease, and therefore also for its communication from Europeans, if this be possible. Nevertheless, far from there being any evidence of epidemics as the result of the introduction of the disease by Europeans