He replied, "Not yet;" and continued, "you are weary, we will rest." He conducted me to a seat on a ledge, and left me for a time. Returning soon, he placed in my hands food which I ate with novel relish. The pabulum seemed to be of vegetable origin, though varieties of it had a peculiar flesh-like flavor. Several separate and distinct substances were contained in the queer viands, some portions savoring of wholesome flesh, while others possessed the delicate flavors of various fruits, such as the strawberry and the pineapple. The strange edibles were of a pulpy texture, homogeneous in consistence, parts being juicy and acid like grateful fruits. Some portions were in slices or films that I could hold in my hand like sections of a velvet melon, and yet were in many respects unlike any other food that I had ever tasted. There was neither rind nor seed; it seemed as though I were eating the gills of a fish, and in answer to my question the guide remarked: "Yes; it is the gill, but not the gill of a fish. You will be instructed in due time." I will add that after this, whenever necessary, we were supplied with food, but both thirst and hunger disappeared altogether before our underground journey was finished. After a while we again began our journey, which we continued in what was to me absolute darkness. My strength seemed to endure the fatigue to a wonderful degree, notwithstanding that we must have been walking hour after hour, and I expressed a curiosity about the fact. My guide replied that the atmosphere of the cavern possessed an intrinsic vitalizing power that neutralized fatigue, "or," he said, "there is here an inherent constitutional energy derived from an active gaseous substance that belongs to cavern air at this depth, and sustains the life force by contributing directly to its conservation, taking the place of food and drink." "I do not understand," I said. "No; and you do not comprehend how ordinary air supports mind and vitalizes muscle, and at the same time wears out both muscle and all other tissues. These are facts which are not satisfactorily explained by scientific statements concerning oxygenation of the blood. As we descend into the earth we find an increase in the life force of the cavern air." This reference to surface earth recalled my former life, and led me to contrast my present situation with that I had forfeited. I was seized with an uncontrollable longing for home, and a painful craving for the past took possession of my heart, but with a strong effort I shook off the sensations. We traveled on and on in silence and in darkness, and I thought again of the strange remark of my former guide who had said: "You are destined to go deeper into the unknown; yes, into and beyond the Beyond." CHAPTER XV. A ZONE OF LIGHT DEEP WITHIN THE EARTH. "Oh! for one glimpse of light, a ray of sunshine!"