ants’-nest cockroaches do not seem to be so, may show that subterranean conditions, contrary to what one might have expected, have affected their efficacy. ------------------------------------------------------------------------ [Illustration: A RIDE ON BEETLE-BACK, AND A LIVING SWEET-SHOP.] Enjoyment seems to be the only motive the fly has for riding on the back of the African beetle shown in the upper part of this illustration. Beneath is shown the well named honey-pot ant with its distended body full of honey, which it gives away to any hungry working ant. A diet of mushrooms, or fungus, is not the only thing for which these little blind, light-shunning cockroaches are indebted to their landlords, the ants, for often one of them may be seen to mount upon one of the latter, and take a ride on its back. They seem especially fond of the soldiers, as horses, and will sit perched on their enormous heads, as they walk up and down in a stately sort of way, sometimes for quite a long time. Enjoyment seems here to be the only motive, and perhaps it is a natural one, since there is a fly in Africa which seems to have quite a passion for riding on the back of a beetle. “Across the mouth of the Seyhouse,” says the Rev. Mr. Eaton, “on sandy pasture-land bordering the seashore, big _coprophagous_ beetles—it sounds abusive, but no harm is meant—are common, sheltering in large holes in the soil, when at rest, and running about on business. A small species of _Borborinæ_ (that is the fly) may often be seen riding on their backs, chiefly on the pronotum and about the bases of the elytra, sometimes half a dozen females on one beetle. The beetles occasionally throw themselves on their backs, and try to get rid of them by rolling; but the flies elude all their efforts to dislodge them, dodging out of harm’s way into the jointures of the thorax, and darting from back to breast, and back again, in a way that drives the beetle nearly mad. In vain she scrapes over them with her legs, in vain does she roll over, or delve down amongst the roots of the herbage: the flies are as active as monkeys (not perhaps a very striking simile here), and there is no shaking them off. It is difficult (such is their strange predilection) to get them off into the killing-bottle. Nothing (not even the killing-bottle) persuades them to fly, and they would very much rather stick to the beetle than——” what? Not go to heaven, but “be driven off it down the tube.”[16] The tube must be the neck of that same bottle. This, surely, is a case of infatuation if ever there was one. Eccentric fly! And what must be the charms of a beetle that can prevail over those of cyanide of potassium! But the beetle, it must be remembered, is a _coprophagous_ one. There may be a world of explanation in a word like that. ----- Footnote 12: