FIG. 3.-Dinka from Fashoda with epithelioma of jaw, secondary glandular involveFrom a photograph by Capt. Ensor, E.M.C., forwarded by

ment.

Dr. A. Balfour, Khartoum.

to vegetarian as well as other castes, and their distribution throughout India suffices to dispel any hopes of discovering races exempt from the disease in that country.

Dr. Keatinge and his coadjutors have reported 297 cases of cancer among the patients treated in the Government Hospitals of Egypt during the past three years. Dr. Balfour of Khartoum has reported sporadic cases from the Sudan (figs. 2 and 3). In short, reports of the occurrence of cancer have been obtained wherever the search has been made, with certain exceptions where the importance of their absence up to date is discounted either by the population being small in numbers, or sparsely scattered over very wide areas. In some instances the apparent absence of cancer loses significance by the fact that investigators in adjacent regions have succeeded in finding it, as, e. g., in the case of some parts of tropical Africa and various Polynesian islands. Dr. Glanville Corney and his colleagues have forwarded a number of specimens from Fiji.

Attempts have of course been made to obtain some computation of the average age attained by aboriginal races among whom cancer appears to be so rare. Dr. Watkins Pitchford states, on behalf of the Natal Cancer Research Committee, " that the estimated native population of Natal in 1906 was 930,000," and commenting on the rarity of cancer among this population he adds, "that whereas 257 per cent. of the population of England and Wales were of the age of 40 and over, only 13.7 per cent of the Natal natives had reached this period of life.” For Natal the definite statement is made that native deaths are reported to the Magistrates by "Informants" who are sent at periodic intervals by the chiefs for this purpose, the cause of the death being usually given as "pain in the head” or “sick inside." Although the Residents and the medical and other officials having long experience in tropical and subtropical Africa and, e. g., New Guinea, express somewhat contradictory views, the balance of opinion favours the surmise that the natives of these regions have not the same expectation of life as is enjoyed in England. The women in many regions have numerous burdens to bear which are unknown in civilised lands and they especially appear to age much in advance of their years. While it is possible that the age-constitution of native populations has much to do with the difficulty of obtaining numerous records of cancer among them, it is impossible definitely to assert that this is really the case, for some observers have reported that a considerable proportion of the male population is over 45 years of Most estimates of age in native races are guesses on the part of

age.

sarcoma.

those who make them, the natives themselves rarely having any idea of the lapse of time. Unless they remember some striking event they can give no assistance.

When the reports of sarcoma are considered as distinct from carcinoma, there is practically no part of the Empire from which reports of the sporadic occurrence of sarcoma have not been received. As pointed out already, the occurrence of sarcoma is as important for the investigation of cancer as the occurrence of carcinoma. The greater ease with which sarcoma has been found may be due to the fact that sarcoma occurs in savage races, as in Europeans, more uniformly throughout life, and is already frequent in those earlier years of life during which the occurrence of carcinoma is still rare.

In dealing with sarcoma in aboriginal races caution is necessary owing to our imperfect knowledge of diseases among them, which may resemble yet be distinct from sarcoma pathologically. Many races exhibit the most extraordinary cheloid growths developing in injuries to the skin either accidentally incurred or deliberately inflicted with a view to adornment. When the adjacent glands become enlarged, as is often the case, the clinical picture may be indistinguishable from that of sarcoma (fig. 4).

It would serve no useful purpose at present to pursue the subject of the ethnological distribution of cancer further. The investigations of the Imperial Cancer Research may be said to have settled once and for all that cancer is a disease common to mankind throughout the world. The questions of its occurrence or non-occurrence having been definitely settled, the problem now presented is its relative frequency in this or that population and area, which overlaps the much discussed question of the alleged increase of cancer, and savage races are unsuited for its study. By the time the natives of Central Africa have so organised their communal life that reliable vital statistics are forthcoming, the conditions of life among them will no longer be what they are to-day, and no doubt they will be interested in what to them may be a new phenomenon, "the alleged increase of cancer." We have seen this stage reached at successive intervals in different countries with the development of their national statistics, and since the work of the Imperial Cancer Research was started Europeans have passed from the belief that cancer was rare or did not occur in Japan, to the minor question of its real or apparent increase in that country.

Like other direct methods of attempting to elucidate cancer problems, it appears as if the study of ethnological distribution has brought us so

far, and then left us face to face with the same pathological problems which limit statistical methods when applied to the cancer-data of England or Europe.

Although the limits of accurate statistical conclusions are quickly reached in reviewing the available data of the incidence of the disease in native races of tropical and subtropical countries, the facts when regarded from another standpoint are full of interest. It is a commonplace of pathology that some organs of the body are more frequently the seat of malignant new growths than others, and, when large numbers of cases are reviewed, the organs of the body can be arranged in a fairly definite order according to the frequency with which cancer originates in them. More than 90 per cent. of the cases reported from tropical and subtropical countries are recorded for sites on the surface of the body or for others very accessible to physical examination. The rarity in the records, of cases from internal organs does not necessarily imply that cancer has a predilection for the surface of the body. The difficulty of diagnosing internal cancer even in well equipped hospitals in London, Scotland, and the Provinces, has already been referred to as of statistical importance; and the same difficulties must be greatly enhanced in degree under the circumstances met with in India, and to a still higher degree among savage races. Various races have the greatest objection to the performance of post-mortem examinations, e. g., Mohammedans. In other regions the belief in sorcery and witchcraft is widespread and places many obstacles in the way of the medical observer. When a savage is afflicted with a painful internal complaint he is not likely to vouchsafe any useful information such as might lead to the diagnosis of advanced cancer. The important additions* surgical operations and post-mortem examinations make to the number of cases of internal cancer recorded in Europe have already been referred to.

An accurate comparison of the English data with those available from India is not possible. Nevertheless a consideration of the crude figures appears to warrant certain tentative conclusions. In India, as in England, cancer is more frequently recorded from some sites than others. The latest Report of the Registrar General includes a table giving the relative quota which the different organs of the body

c