254 APES AXD MONKEYS 



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 awav, and Moses was sitting on a dead 

 loo- near bv. I turned to him and was in the act of sitting 

 down bv 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. 



One dav I heard three sounds which a native bov assured 

 me were made by gorillas ; they were in different direc- 

 tions from the cage. It was not a scream nor a howl, but 

 somewhat resembled the human voice calling out with a 

 sound like "he-oo!" These sounds were repeated at 

 intervals, but did not appear to be in the relation of call 

 and answer ; and the animals making them did not approach 

 each other while calling. The sounds were the same except 

 in volume. One of them appeared to be made by an ani- 

 mal much larger than the animals that had made the 

 two other sounds. I should state that this sound rarely 

 occurred within my hearing during my stay in that part, 



