Immediately they saw him, they rose and clustered about him, the girls pushing the boys aside and coming boldly close, and Tarzan spoke to them, first in one native dialect and then in another, but they seemed not to understand, for they made no reply, and then, as a last resort, he addressed them in the primitive language of the great apes, the language of Manu the monkey, the first language that Tarzan had learned when, as a babe, he suckled at the hairy breast of Kala, the she-ape, and listened to the gutturals of the savage members of the tribe of Kerchak; but again his auditors made no response--at least no audible response, though they moved their hands and shoulders and bodies, and jerked their heads in what the ape-man soon recognized as a species of sign language, nor did they utter any vocal sounds that might indicate that they were communicating with one another through the medium of a spoken language. Presently they again lost interest in the newcomer and resumed their indolent lounging about the walls of the courtyard while Tarzan paced to and fro its length, his keen eye searching for whatever avenue of escape chance might provide, and he saw it in the height of the walls, to the top of which a long, running jump would take his outstretched fingers, he was sure; but not yet--he must wait for darkness to shield his attempt from those within the enclosure and those without. And as darkness approached the actions of the other occupants of the courtyard became noticeably altered; they walked back and forth, constantly passing and repassing the entrance to the shelter at the end of the courtyard, and occasionally entering the first room and often passing to the second room where they listened for a moment before the great slab that closed the outer aperture; then back into the courtyard again and back and forth in restless movement. Finally one stamped a foot upon the ground and this was taken up by the others until, in regular cadence, the thud, thud, thud of their naked feet must have been audible for some distance beyond the confines of their narrow prison yard. Whatever this procedure might have been intended to accomplish, nothing, apparently, resulted, and presently one of the girls, her sullen face snarling in anger, seized her bludgeon more firmly in her two hands and stepping close to one of the walls began to pound violently upon one of its huge stone slabs. Instantly the other girls followed her example, while the young males continued beating time with their heels. For a while Tarzan was puzzled for an explanation of their behavior, but it was his own stomach that at last suggested an answer--the creatures were hungry and were attempting to attract the attention of their jailers; and their method of doing so suggested something else, as well, something of which his past brief experience with them had already partially convinced him--the creatures were without speech, even totally unvocal, perhaps.