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the picking is finished, watering is discontinued, and the systematic destruction of snails in the canals is commenced.

(ii) A small filtration into the Gezirah takes place from infected areas in Berber and Dongola Provinces. The numbers concerned are small, and it is hoped to be able to find and cure these people soon after their arrival. They are easier to deal with than the other three classes, moreover they tend to live in the old established villages where wells exist.

Conclusion. It has been pointed out above that infected snails have been found in four canals and it is probable that if a long enough search were made, occasional infected snails would be found in other canals. It has been mentioned also that a few children have contracted this disease since 1926. The position, however, would not appear to be hopeless. It should be possible to kill all the snails in the distributary canals during the non-watering season of 1929 and thus the canals would start afresh when watering recommences, infested with snails it is true, but with uninfected snails.

It is doubtful if we can make the quarantine measures on the White Nile much more effective than they are at present, but it is hoped that by inspecting and treating the Takrooris pilgrims in their villages and by searching for and isolating until cured all infected westerners, it will be possible to find and cure the great majority of the infected persons who have escaped detention at the

quarantine stations.

It is hoped also, by continued propaganda and by the enforcement of police regulations, to prevent to an increasing extent the contamination of the canals by infected persons and of the people by infected canals. In the future we have a good deal to hope for from further study of the habits of the snails and of methods designed to prevent their introduction into and their propagation in the canals.

The position then as to the likelihood of the permanent infection of this area and as to the serious consequences to the health efficiency of the population which would inevitably result appears to be grave, but by no means without hope of prevention.

BLACKWATEE FEVER.

Twenty one cases of blackwater fever were reported. The distribution was as follows : —

Province Hospital Nationality Result

Berber . . Atbara 1 Egyptian Recovered Dongola Dongola 1 Native yy Blue Nile Wad-Medani 1 „ * $

yy Makwar 1 „ Died Kordofan El-Obeid 2 Natives 1 & 1 recovered

yy 2 Syrians 1 >, & 1

yy Nahud 2 Natives Recovered Kassala . . Kassala 1 Native Fung Roseires 2 Natives Upper Nile Malakal 3 „ 2 died & 1 recovered

* % ., from Gambela 1 Swiss man Died Nuba Mountains Talodi 1 Greek girl Recovered

yy Kadugli 1 Syrian yy Mongalla Juba ] Khartoum native Died

yy Lul 1 Italian priest Recovered