And yet the ants of Africa are the chief agents employed in forming a fertile soil. “But for their labors,” remarks Dr. Livingstone, “the tropical forests, bad as they now are with fallen trees, would be a thousand times worse. They would be impassible on account of the heaps of dead vegetation lying on the surface, and emitting worse effluvia than the comparatively small unburied collections do now. When one looks at the wonderful adaptations throughout creation, and the varied operations carried on with such wisdom and skill, the idea of second causes looks clumsy. We are viewing the direct handiwork of Him who is the one and only Power in the universe; wonderful in counsel; in whom we all live, and move and have our being.” There are vast numbers of annoying insects in all portions of the continent, which in this respect, perhaps, is neither better nor worse than other parts of the world, where little annoyances make up the great sum of human misery. It is only one of many proofs that Africa is the region of contrasts, that the greatest animals flee from a little insect, the life of scores of whom might be stamped out by a single footstep, yet the aggregate labors of which preserve the continent from desolation and decay. [Illustration] [Illustration: INSECT NEST-BUILDING.] CHAPTER XV. LIVINGSTONE’S LAST JOURNEY AND DEATH. Dr. Livingstone anxiously awaits the Recruits and Supplies sent by Mr. Stanley -- On their Arrival sets out Southwestward on his Last Journey -- Reaches Kisera, where Chronic Dysentery seizes him -- He refuses to yield; but pushes on, till Increasing Debility compels him to stop and retrace his steps -- He sinks rapidly, and on May 4th Breathes his Last -- His attendants take Necessary Precautions to Insure the Return of the Corpse to England -- Letter from Mr. Holmwood, Attaché of the British Consulate at Zanzibar. It will be recollected that Stanley bade Dr. Livingstone farewell on the 14th of March, 1872, at Kwihara, and that, on his arrival at Zanzibar, he sent back to Dr. Livingstone the men and means he had expressed a wish for.