HABITS OF THE GORILLA 221 



I know of nothing in the way of vocal sounds that 

 can inspire such terror as the voice of the gorilla. It 

 can be heard over a distance of three or four miles. 

 I could assign no definite meaning to it unless it was 

 intended to alarm some intruder that came too 

 near. 



One morning between three and four o'clock I 

 heard two of them screaming at the same time. I 

 do not mean to say at the same instant, but at 

 intervals during the same period of time. One of 

 them was within about a third of a mile of me, and 

 the other in another direction perhaps a mile away. 

 The points we occupied respectively formed a 

 scalene triangle. The sounds did not appear to 

 have any reference to each other. Sometimes they 

 would alternate, and at other times they would 

 interrupt each other. They were both made by 

 giants of their kind, and every leaf in the forest 

 vibrated with the sound. This was during the latter 

 part of May. They do scream in this way from time 

 to time throughout the year, but it is most frequent 

 and violent during February and March. 



This wild screaming is sometimes accompanied by 

 a peculiar beating sound. It has been described by 

 travellers, and currently believed to be made by the 

 animal beating with his hands upon his breast ; but 

 such is not the case. It is very certain that the 

 sound cannot be made by that means. The quality 

 of the sound shows that such cannot be the means 

 employed. I have heard this beating several times, 

 and have paid marked attention to its character. At 



