In the tropical warfare which was before us medical care is one of the most important factors. Generally speaking, the native is in a great measure immune against malaria, and it does not often happen that an Askari gets really ill with it; some tribes, however, like the Wajagga, on Kilima Njaro, who inhabit elevated, non-malarial districts, and are therefore not immune from early youth, suffer severely from malaria as soon as they come down to the plains. From the evening until well into the morning mechanical protection against the malaria mosquito (anopheles), by means of a mosquito net, was strictly enforced for every European. For many months I slept on the ground, and even then the mosquito-net afforded me a high degree of protection; even so I had malaria ten times, for in the field it is not always possible to employ preventive measures to the extent that is desirable from a hygienic point of view. In our endeavour to attach a medical officer to every company we received most welcome assistance from the fact that there was a considerable number of them on Lake Tanganyika, and in the Southern territories on the Rovuma, who had come out to study and combat sleeping-sickness. The work entailed by all this business of mobilization not only kept us going day and night, but also the native telephonist at Pugu, and it was extraordinary to see the skill with which the black man worked his instrument, both there and elsewhere. His great technical talent proved of the greatest value to us. Of difficulties there was, of course, an infinity. During the early days it happened that cattle coming from the country north of Tabora for the civilian population at Dar-es-Salaam met other cattle going in the opposite direction to feed the troops. To this day I feel something of a physical shock when I think of a collision at Pugu, between a train laden with the finest show cattle going at full speed, and another one, which nearly produced a serious reduction in the personnel required for working out our mobilization scheme.