36 in my opinion, since the introduction of vaccination, taken the place of small-pox as the chief cause of child mortality in the whole tribe. Other causes of child mortality are chiefly infantile diarrhoea, congenital syphilis or yaws, pneumonia and bronchitis.

Amongst the adult population one is struck by the large numbers of healthy old people. This is I think attributable to the very appreciable decrease in the last few years of interfamily feuds and strifes which used invariably to result in deaths on both sides.

Epidemiology. In 1919 an epidemic of small-pox swept through the whole tribe and practically decimated the people. The lesson in prophylactic vaccina¬ tion learnt then is still fresh in their minds, and has considerably eased the work of teaching prophylaxis in all directions. No serious epidemic has occurred since that time.

General Diseases. The following is a list of diseases.encountered during the survey. These have been tabulated in accordance with Sudan Medical Service Form No. 20 and will be dealt with in that order.

Tubercular :— (a) Pulmonary tuberculosis appears to be a new disease amongst the tribe and its control requires careful observation. Twenty men and two women were found infected. These were mostly adults and amongst the men at least, infec¬ tion usually originated from some time when the patient had lived at places like Malakal, Kodok, Tonga or had travelled further afield. The youngest cases infected were two boys both aged 18 years.

(b) Surgical tuberculosis. Five cases of definite tuberculosis of bones were found. This is certainly lower than the actual figure, but the increasing populari¬ ty of Malakal hospital attracts many cases of this kind. The correct figure of all cases wmuld probably be about ten.

(c) Adenitis. Seventeen cases of general adenitis W'ere found. 75 per cent, of these occurred in children, but with the prevailing incidence of syphilis and yaws I am not prepared to diagnose these as definitely tubercular.

From these figures it may be concluded that tuberculosis is not an endemic disease amongst the Shilluks and the disease is probably introduced through contact with infected Arabs and others. Were the disease endemic one wxmld expect to find a very definite number of children infected even though bovine tuberculosis is extremely rare in the province.

Venereal disease—Gonorrhoea. Though no case of primary gonorrhoea was treated during the trek there is every reason to suspect its existence. The disease is certainly prevalent in Kodok and Malakal amongst the Malakia, as is shown by hospital attendances. A woman might certainly conceal the disease as its existence would considerably decrease her market value in the eyes of a pros¬ pective suitor. Outside those Merakiz, however, the disease is not likely to establish itself widely as the tribe as a whole is really very moral—the penalty for immorality being very severe. Sequelae—Four cases of gonorrhoeal orchitis were dealt with.

Syphilis and Yaws. Unfortunately those two conditions must be con¬ sidered together as it is in most cases impossible to differentiate between late yaws, tertiary syphilis and congenital syphilis.

Three cases only of undoubtable primary chancre and one of secondary syphilis presented themselves for treatment. This is remarkable in view of the large numbers of cases showing lesions resembling tertiary and congenital