Having caught a specimen of this fly, I next proceeded to institute a comparison between it and the tsetse, as described by Dr. Livingstone on pp. 56-57, `Missionary Travels and Researches in South Africa’ (Murray’s edition of 1868).  The points of disagreement are many, and such as to make it entirely improbable that this fly is the true tsetse, though my men unanimously stated that its bite was fatal to horses as well as to donkeys.  A descriptive abstract of the tsetse would read thus:  “Not much larger than a common house-fly, nearly of the same brown colour as the honey-bee.  After-part of the body has yellow bars across it.  It has a peculiar buzz, and its bite is death to the horse, ox, and dog.  On man the bite has no effect, neither has it on wild animals.  When allowed to feed on the hand, it inserts the middle prong of three portions into which the proboscis divides, it then draws the prong out a little way, and it assumes a crimson colour as the mandibles come into brisk operation; a slight itching irritation follows the bite.”

The fly which I had under inspection is called mabunga by the natives.  It is much larger than the common housefly, fully a third larger than the common honey-bee, and its colour more distinctly marked; its head is black, with a greenish gloss to it; the after-part of the body is marked by a white line running lengthwise from its junction with the trunk, and on each side of this white line are two other lines, one of a crimson colour, the other of a light brown.  As for its buzz, there is no peculiarity in it, it might be mistaken for that of a honey-bee.  When caught it made desperate efforts to get away, but never attempted to bite.  This fly, along with a score of others, attacked my grey horse, and bit it so sorely in the legs that they appeared as if bathed in blood.  Hence, I might have been a little vengeful if, with more than the zeal of an entomologist, I caused it to disclose whatever peculiarities its biting parts possessed.

In order to bring this fly as life-like as possible before my readers, I may compare its head to most tiny miniature of an elephant’s, because it has a black proboscis and a pair of horny antennae, which in colour and curve resemble tusks.  The black proboscis, however, the simply a hollow sheath, which encloses, when not in the act of biting, four reddish and sharp lancets.  Under the microscope these four lancets differ in thickness, two are very thick, the third is slender, but the fourth, of an opal colour and almost transparent, is exceedingly fine.  This last must be the sucker.  When the fly is about to wound, the two horny antennae are made to embrace the part, the lancets are unsheathed, and on the instant the incision is performed.  This I consider to be the African “horse-fly.’