A correct idea of the anatomy of the little crab may be obtained from my illustration. But what is it all about, this funny ride on a fly's hind-leg? Excepting as an inconvenience and encumbrance it is doubtful whether the fly is much the worse for his close attachment, and while this mimic crab or lobster cannot be called a frequent passenger, a careful scrutiny of any considerable assemblage of flies on white paper or window-pane will occasionally show us the animated and persistent red tag.
But let us call him a lobster no more, rather one of the "False Scorpions," one of the group known as Pedipalpi, in the books: queer little creatures that live in dusty nooks, among old books and papers, and feed on tiny mites and other minute life which harbor them, but born rovers withal, with a singular fancy for fly-toes and free rides.
But the false scorpion may be considered rather as a bother than a serious trouble to the fly. His real troubles are too numerous to mention. His life, as most of my readers will be glad to learn, is not a bed of roses, as is commonly supposed. Just think for a moment what a fly's existence must be. With the deadly fly-paper on the one hand, the continual danger of being cemented into a pellet of pulp in the maw of a hornet, or impaled on the beak of his murderous relative the "Laphria-fly," or snapped up by birds, toads, snakes, he certainly has abundant use for that head full of eyes of his. All summer long he runs the gantlet of risks like these, but in September and October a new and terrible danger awaits him, and fortunate is he if he escapes in these advanced days of scientific discovery, when so many of our mortal ills are shown to be dependent upon the malignity of hovering germs, of microbes, bacteria, and bacilli.
Let us be thankful we have at least escaped the notice of one of this insidious throng, and are spared the grotesque horror of such a fate as the germ-scourge of flydom. How swift and terrible is its course! Today a pert and gladsome innocent, sipping on the rim of our dinner-plate; to-morrow a pale, dry relic of his former self, hanging from the window-pane by its tongue, and enveloped in a white shroud of mould, the victim of a germ or spore. Look where we will upon the window on those September and October days and we see the little smoky cloud with the dangling fly in its midst, and many an apparently modest and considerate fly upon the wall will be found similarly fixed to the surface, and surrounded with the white nimbus.
But the real mischief was done perhaps early in the evening, after our fly had retired for the night. He presumably experienced the first attack of acute dyspepsia he had ever known. In his promiscuous feeding he had chanced to imbibe a spore, which once within his vitals began its murderous work, growing so fast as to completely fill his swelling body by morning, when, having completed its growth and penetrated through the insect's skin, it spread its own spores, to be wafted hither and yon to the peril of next year's flies, and the consequent delight of the tidy house-keeper.
Such is the work of the world-renowned fly-fungus, of which a writer says: "It silences more house-flies than all the brushes, traps, poisons, whacks, and swearing devoted to the extermination of the insect."
