The heat of the sun had hardly driven the _igooguai_ out of the field and obliged them to take shelter in the forest or somewhere else (for during the heat of the day they do not trouble any one), than the flies—which we might call the three plagues—the _iboco_, the _nchouna_, and the _ibolai_, began to make their appearance. These are quiet in the morning, and remain so until the sun has warmed the atmosphere, then they begin to buzz around the people; hence, as you see, there was no peace for poor me. I had hardly got rid of one kind of the igooguai when I got into the hands of these three other suckers by way of a change. In certain regions, from eleven o’clock till three, I certainly thought I should lose my senses, especially when living on the banks of rivers. The most dreaded of all, and the most savage of these three species of flies, is the _iboco_. I shall never forget the iboco as long as I live. I have been stung too many times by them to forget it. A hot day, and under a powerful sun, these insects attacked us with a terrible persistency that left us no peace. The iboco is a large fly of the size of a hornet, with yellow body and a large green head; it flies with a wonderful rapidity; and when it wants to rest on somebody it whirls round and round so rapidly that the eyes become quite bewildered, and in the wink of an eye they rest on the bare back of some poor negro, and give a sting which draws often from him a cry of anguish. There is always great rejoicing when an iboco is killed. They are very plentiful in the regions of the Ovenga River; indeed, I have never seen them in such great numbers anywhere else. They like to be by the water and in open places. I have never seen them except in the clearings. Many and many times have I started as if stung by a scorpion or centipede, when it was nothing but an iboco, whose bill had gone through two or three of my garments. Their bite is quite as painful as that of a scorpion, but happily it is not venomous, and the pain does not last long; but its sharpness makes up for the shortness of its duration. Often the blood has run down my face or arm, from their savage attacks, and even the well-tanned skin of the negroes is punctured till it bleeds, so that one would almost think that a leech had been at work on them. [Sidenote: _THE NCHOUNA._] The _nchouna_ has quite another sort of tactics. It is not so large as the iboco, is far more sly, and is also found in greater numbers. If the iboco were as numerous as the nchouna, the people would surely not be able to live in the regions of the Ovenga. The nchouna is somewhat of the shape of our common flies, but of at least twice the size; it is of a yellowish color, and perhaps more elongated, resembling very much the _tsetche_ of Southern Africa, of which species it may be a variety.