"Good work, Tippet," he said. "Mightily obliged to you—awful waste of ammunition, really."

And then they resumed the march and in fifteen minutes the encounter had ceased even to be a topic of conversation.

For two days they continued upon their perilous way. Already the cliffs loomed high and forbidding close ahead without sign of break to encourage hope that somewhere they might be scaled. Late in the afternoon the party crossed a small stream of warm water upon the sluggishly moving surface of which floated countless millions of tiny green eggs surrounded by a light scum of the same color, though of a darker shade. Their past experience of Caspak had taught them that they might expect to come upon a stagnant pool of warm water if they followed the stream to its source; but there they were almost certain to find some of Caspak's grotesque, manlike creatures. Already since they had disembarked from the U-33 after its perilous trip through the subterranean channel beneath the barrier cliffs had brought them into the inland sea of Caspak, had they encountered what had appeared to be three distinct types of these creatures. There had been the pure apes—huge, gorillalike beasts—and those who walked, a trifle more erect and had features with just a shade more of the human cast about them. Then there were men like Ahm, whom they had captured and confined at the fort—Ahm, the club-man. "Well-known club-man," Tyler had called him. Ahm and his people had knowledge of a speech. They had a language, in which they were unlike the race just inferior to them, and they walked much more erect and were less hairy: but it was principally the fact that they possessed a spoken language and carried a weapon that differentiated them from the others.