After a time, I noticed that my feet were becoming warm, and realised that the sand must be heated, though not so much so as the soil on which I had walked previously. I did not think it to be sufficiently so to constitute a serious danger, or discomfort, but I considered that it might be a different matter to a foot protected only by its own fur, and, supposing that I had found the explanation of the warning, and that it did not affect me, and being somewhat short of breath from the long spurt I had taken, I slackened to a quieter walk,--and as my right foot came down, a pink streak shot out of the sand a few inches from it, and smacked against my ankle, with a sound like a whip lash. I jumped, with a cry of horror, or at least I tried to jump, and came down on my hands, for the grip held, and I was powerless to break it. The pink worm did not twine round my foot, but lay up the side, holding on, leech-like, by power of suction. It was trying to drag the foot into the sand, but, for the moment, that was beyond its power. Wrenching desperately, I tried to get loose the axe, for which I had expected no use, and which was slung on my back, under the knapsack, for convenience as I ran. When I got it clear I realised that I could not strike hard against my own ankle, and to an attempt at cutting, my assailant showed the resilient rubber-like quality which seemed common to several of the forms of life with which I was becoming familiar. With a despairing effort I strained my foot a few inches from the ground, and drove a hard blow beneath it, at which the severed worm fell writhing on the sand. But now there were two others round my left foot, and their united strength was too great for me to lift it to enable me to deal with them in the same way. I gave up the axe, and hacked them free with the clasp knife. Then I saw that the ground behind me, and for several yards in front, showed similar worms that had pushed up through the sand, and waved and felt around for the origin of the vibrations which had disturbed them. No doubt they had been rising behind me all the time, but I had passed over the ground so quickly that I had always been in advance of my danger, and unaware that it threatened me. I suppose that the roots of the plants without,--if plants they could be called,--grew under the wall of the tunnel, and lived among the sand, though the conditions did not allow of the leaves shooting up in such soil, or in the absence of the light they needed. I noticed with some relief that the surrounding tongues could not reach me while I remained motionless, and I concluded that they must be in some way rooted, or growing from a common source, which kept them in their places securely.