CAIRO TO KISUMU its explorers are sent out in every direction to make all sorts of researches. They are studying the mosquitoes of the country and are investigating the tsetse fly and other pests. Among other evils they are fighting the sleeping sickness, that horrible disease communicated by the tsetse fly which has killed its thousands throughout Central Africa. They are trying to rout the boll weevil and other insects which ruin the crops, and they are aiding the Cancer Research Fund and the Carnegie Institute in their inquiries. I have met a number of the scientists connected with this institution and I find them able men. They tell me that the Sudan has almost every noxious insect and pest known to man. It has worms and wee¬ vils which affect the cotton crop, and it has mosquitoes which carry malaria and which would carry yellow fever if they were once inoculated by feeding upon a yellowfever patient. Indeed, the stegomyia, or yellow-fever mosquito, swarms here, and if one of them should be im¬ pregnated with these disease germs it might start an end¬ less chain of the scourge which could hardly be broken.

The chemists here tell me that one of the principal money crops of this part of the world is gum arabic. We know this gum chiefly in connection with mucilage, but it is also widely used in the arts. It is employed for mak¬ ing water colours and certain kinds of inks as well as in dyeing and finishing silks and other fabrics. Some of the better grades are used in confectionery, and the pearly teeth of many an American girl have done their work in the chewing of this exudation of the trees of the Sudan. The gum, which comes from the acacia tree, is said to be due to a microbe which feeds upon the sap and causes the gum to ooze out on the bark in the form of tears when 206