by night; to go on deck by day was to be blinded by glare and to stay below was to suffocate.  And in the daytime came certain flies, extremely clever and noxious about one’s wrist and ankle.  Captain Gerilleau, who was Holroyd’s sole distraction from these physical distresses, developed into a formidable bore, telling the simple story of his heart’s affections day by day, a string of anonymous women, as if he was telling beads.  Sometimes he suggested sport, and they shot at alligators, and at rare intervals they came to human aggregations in the waste of trees, and stayed for a day or so, and drank and sat about, and, one night, danced with Creole girls, who found Holroyd’s poor elements of Spanish, without either past tense or future, amply sufficient for their purposes.  But these were mere luminous chinks in the long grey passage of the streaming river, up which the throbbing engines beat.  A certain liberal heathen deity, in the shape of a demi-john, held seductive court aft, and, it is probable, forward.

But Gerilleau learnt things about the ants, more things and more, at this stopping-place and that, and became interested in his mission.

“Dey are a new sort of ant,” he said.  “We have got to be—­what do you call it?—­entomologie?  Big.  Five centimetres!  Some bigger!  It is ridiculous.  We are like the monkeys—–­sent to pick insects...  But dey are eating up the country.”

He burst out indignantly.  “Suppose—­suddenly, there are complications with Europe.  Here am I—­soon we shall be above the Rio Negro—­and my gun, useless!”

He nursed his knee and mused.

“Dose people who were dere at de dancing place, dey ’ave come down.  Dey ’ave lost all they got.  De ants come to deir house one afternoon.  Everyone run out.  You know when de ants come one must—­everyone runs out and they go over the house.  If you stayed they’d eat you.  See?  Well, presently dey go back; dey say, ’The ants ‘ave gone.’ ...  De ants ’aven’t gone.  Dey try to go in—­de son, ’e goes in.  De ants fight.”

“Swarm over him?”

“Bite ’im.  Presently he comes out again—­screaming and running.  He runs past them to the river.  See?  He gets into de water and drowns de ants—­ yes.”  Gerilleau paused, brought his liquid eyes close to Holroyd’s face, tapped Holroyd’s knee with his knuckle.  “That night he dies, just as if he was stung by a snake.”

“Poisoned—­by the ants?”

“Who knows?” Gerilleau shrugged his shoulders.  “Perhaps they bit him badly...  When I joined dis service I joined to fight men.  Dese things, dese ants, dey come and go.  It is no business for men.”

After that he talked frequently of the ants to Holroyd, and whenever they chanced to drift against any speck of humanity in that waste of water and sunshine and distant trees, Holroyd’s improving knowledge of the language enabled him to recognise the ascendant word Saueba, more and more completely dominating the whole.