He gave it up. Sufficient for the moment that they were unmolested, and that he had a chance at first hand to make observations more complete than the world of entomology had ever dreamed of. * * * * * They stumbled onto what seemed a death struggle between one of the giant soldiers and an inoffensive-looking worker. The drab, comparatively feeble body of the worker was wriggling right in the center of the great claws which, with a twitch, could have sliced it in two endwise. Yet the jaws did not twitch; and in a few moments the worker drew unconcernedly out and moved away. "The soldier was getting his meal," whispered Denny, enthralled. "Their mandibles are enlarged so enormously that they can't feed themselves. The workers, who digest food for the whole tribe, feed them regularly. Then if a soldier gets in the least rebellious, he can simply be starved to death at any time." "Ugh!" Jim whispered back. "Fancy being official stomach to three or four other people! More of your wonderful 'organization,' I suppose." They went on, down and down, till Denny calculated they had at last reached nearly to the center of the vast city. And now they stumbled into something weird and wonderful indeed. Rather, they half fell into it, for it lay down a few feet and came as a complete surprise in the dimness; and not till they had recovered from their near fall and looked around for a few seconds did they realize where their last few steps--the last few steps of freedom they were to have in the grim underground kingdom--had taken them. They were in a chamber so huge that it made the largest of man-made domes shrink to insignificance by comparison. * * * * * A hundred yards or more in every direction, it extended. And far overhead, lost in distance, reared the arched roof. A twenty-story building could have been placed under that roof without trouble. Lost in awe, Dennis gazed about him; and he saw on the floor, laid in orderly rows in countless thousands, that which gave further cause for wonderment: new-hatched larvae about the size of pumpkins but a sickly white in color--feeble, helpless blobs of life that one day develop into soldiers and workers, winged rulers or police. The termite nursery. "Whew!" gasped Jim, wiping his face. "From the heat in here you'd think we were getting close to the real, old-fashioned hell instead of an artificial, insect-made one. What are all these nauseating-looking blobs of lard lying about here, anyway?" Denny told him. "Which is the reason for the heat," he concluded. "Jim, it's twenty degrees warmer in here than it is outdoors. How--_how_--can these insects regulate the temperature like that? The work of the ruling brain again? But where, and what, can that brain be?"