This we found out soon after we entered the swamp, since Robertson, pushing forward with the fierce eagerness which seemed to consume him, neglected to keep his eye upon the spoor and stepped off the edge on to land that appeared to be exactly similar to its surface.  Instantly he began to sink in greasy and tenacious mud.  Umslopogaas and I were only twenty yards behind, yet by the time we reached him in answer to his shouts, already he was engulfed up to his middle and going down so rapidly that in another minute he would have vanished altogether.  Well, we got him out but not with ease, for that mud clung to him like the tentacles of an octopus.  After this we were more careful.

Nor did this road run straight; on the contrary, it curved about and sometimes turned at right angles, doubtless to avoid a piece of swamp over which it had proved impossible for the ancients to construct a causeway, or to follow some out-crop of harder soil beneath.

The difficulties of that horrible place are beyond description, and indeed can scarcely be imagined.  First there was that of a kind of grass which grew among the roots of the reeds and had edges like to those of knives.  As Robertson and I wore gaiters we did not suffer so much from it, but the poor Zulus with their bare legs were terribly cut about and in some cases lame.

Then there were the mosquitoes which lived here by the million and all seemed anxious for a bite; also snakes of a peculiarly deadly kind were numerous.  A Zulu was bitten by one of them of so poisonous a nature that he died within three minutes, for the venom seemed to go straight to his heart.  We threw his body into the swamp, where it vanished at once.

Lastly there was the all-pervading stench and the intolerable heat of the place, since no breath of air could penetrate that forest of reeds, while a minor trouble was that of the multitude of leeches which fastened on to our bodies.  By looking one could see the creatures sitting on the under side of leaves with their heads stretched out waiting to attack anything that went by.  As wayfarers there could not have been numerous, I wondered what they had lived on for the last few thousand years.  By the way, I found that paraffin, of which we had a small supply for our hand-lamps, rubbed over all exposed surfaces, was to some extent a protection against these blood-sucking worms and the gnats, although it did make one go about smelling like a dirty oil tin.

During the day, except for the occasional rush of some great iguana or other reptile, and the sound of the wings of the flocks of wildfowl passing over us from time to time, the march was deathly silent.  But at night it was different, for then the bull-frogs boomed incessantly, as did the bitterns, while great swamp owls and other night-flying birds uttered their weird cries.  Also there were mysterious sucking noises caused, no doubt, by the sinking of areas of swamp, with those of bursting bubbles of foul, up-rushing gas.