One day as I sat alone a young gorilla, perhaps five years old, came within six or seven yards of the cage and took a peep. I do not know whether or not he was aware of its being there until he was so near. He stood for a time, almost erect, with one hand holding on to a bough. His lower lip was relaxed, showing the red line mentioned elsewhere, and the end of his tongue could be seen between his parted lips. He did not evince either fear or anger, but rather appeared to be amazed. I heard him creeping through the bush a few seconds before I saw him. As a rule, they move so stealthily as not to be heard. I know of no other animal of equal size that makes so little noise in going through the forest. During the short time he stood gazing at me I sat still as a statue, and I think he was in doubt as to whether or not I was alive. He did not run away, but after a brief pause turned off at an angle and quietly departed. He lost no time, but made no great haste. The only sound he made was a low grunt, and this he did not repeat. At another time I heard two making a noise among the plantains near me. I could obtain only a glimpse of them, but as well as I could see they were of good size, being almost grown. They were making a low sound from time to time, something such as I have described; but I could not see them well enough to frame any opinion as to what it meant. They were certainly not quarreling, and I was not sure that they were eating. I afterwards went and looked to see if I could find where they had broken any of the stalks. Their trail was visible through the grass and weeds, but I could find no broken stalk. They were moving at a very leisurely gait and must have been within hearing distance some ten or twelve minutes. They were quite alike in color and appeared to be so in size, although the adult male attains a much greater size than the female. On one occasion I was standing outside of the cage some twenty yards away, and Moses was sitting on a dead log near by. I turned to him and was in the act of sitting down by him when he gave alarm. This he did in an undertone, apparently to avoid attracting the attention of the thing against which the warning was intended. I looked around, and discovered a gorilla standing not twenty yards away. He had just discovered us. He gazed for a moment and started on, moving obliquely towards the cage. I turned to retreat. At this instant Moses gave one of his piercing screams, which frightened the gorilla and he fled. He changed his course almost at right angles. He was going at a good rate before Moses screamed, but he at once increased his pace.