Early next morning we were again afoot, and found that the character of the country had changed once again. Behind us was the wall of bamboo, as definite as if it marked the course of a river. In front was an open plain, sloping slightly upwards and dotted with clumps of tree-ferns, the whole curving before us until it ended in a long, whale-backed ridge. This we reached about midday, only to find a shallow valley beyond, rising once again into a gentle incline which led to a low, rounded skyline. It was here, while we crossed the first of these hills, that an incident occurred which may or may not have been important.

Professor Challenger, who with the two local Indians was in the van of the party, stopped suddenly and pointed excitedly to the right. As he did so we saw, at the distance of a mile or so, something which appeared to be a huge gray bird flap slowly up from the ground and skim smoothly off, flying very low and straight, until it was lost among the tree-ferns.

“Did you see it?” cried Challenger, in exultation. “Summerlee, did you see it?”