But the black fly is at the bottom of the moral scale. He is an unmitigated ruffian, the plug-ugly of the woods. He looks like a tiny, immature house-fly, with white legs as if he must be innocent. But, in fact, he crawls like a serpent and bites like a dog. No portion of the human frame is sacred from his greed. He takes his pound of flesh anywhere, and does not scruple to take the blood with it. As a rule you can defend yourself, to some degree, against him, by wearing a head-net, tying your sleeves around your wrists and your trousers around your ankles, and anointing yourself with grease, flavoured with pennyroyal, for which cleanly and honest scent he has a coarse aversion. But sometimes, especially on burned land, about the middle of a warm afternoon, when a rain is threatening, the horde of black flies descend in force and fury knowing that their time is short. Then there is no escape. Suits of chain armour, Nubian ointments of far-smelling potency, would not save you. You must do as our guides did on the portage, submit to fate and walk along in heroic silence, like Marco Bozzaris "bleeding at every pore,"--or do as Damon and I did, break into ejaculations and a run, until you reach a place where you can light a smudge and hold your head over it.