V\ ith regard to the irrigation area in the Gezirah: It has I believe been discovered that much better Cotton is obtained from areas on which the intermediate crop lias been grazed off by cattle and sheep, than from areas not so manured. This indicates a large animal population in this area. Furthermore it suggests that as the population will be sedentary, and the conditions for the control of disease favourable, every endeavour should be made to grade up the cattle and sheep in this area by imported sires, and thus to obtain a much more marketable animal than at present exists. This would mean the double inoculation of all the cattle in the area against Rinderpest, and their inoculation also with Contagious Bovine Pleuro¬ pneumonia vaccine. Prior to this there would have to be a very careful census of all animals, and the establishment of a cordon, and strict prohibition of the movement of all animals into the area from outside except through a quarantine. As Cattle Plague would be continually being introduced by indirect means, the process of inoculation of the young stock would have to be continued. With regard to Pleuro-pneumonia we are faced with the difficulty of the chronic carrier, but as these carriers are not usually infective for much more than a year, and the protection afforded by the vaccination lasts two years, the actual carriers already present should be innocuous before the animals again become susceptible. The trouble is the unknown animal from outside which may be a carrier. It may be possible to test all animals before entry into the area by means of the conglutination test, but this is a process requiring considerable laboratory skill and would be reliable only in the hands of a trained bacteriologist.

This double inoculation raises the question of a Research and Serum Institute, It is highly improbable that we should be able to obtain serum in sufficient quantities from other Institutes, particularly as the one in Egypt will close down when they have completed the double inoculation of their cattle. Furthermore, it has been noticed that when there is a heavy demand for serum in one country, there is also a heavy demand in the country in which the Institute exists, and it has none to spare. In other words heavy invasions of Rinderpest appear to be world wide in their cyclic incidence in countries in which the disease exists. Also the serum from countries such as India may lose its protective power owing to the heat to which it is subjected during the journey. The Serum Institute would have to be in the Red Sea Mills, as Khartoum, owing to conditions of wind, dust, sand and temperature is totally unsuitable for one. The research work could be most conveniently carried out in Khartoum as at present, as