CHAPTER XIII. 



The Extent of my Experiments. — Apes and Baboons. — Miscel- 

 laneous Records of Sounds. — The Vocal Index. 



In quest of the great secret of speech, I have 

 pursued my investigations chiefly in the direction 

 of learning one tongue, but incidentally I have 

 made many detours, and I have recorded the 

 sounds of many other forms of the animal king- 

 dom besides primates. I have examined the 

 phonation of lions, tigers, leopards, cats, dogs, 

 birds of many kinds, and the human voice in 

 speech, music, and laughter. Besides these I 

 have examined various musical sounds, especially 

 of the pipe and whistle kinds. 



More than a year ago I made some splendid 

 records of the sounds of the two chimpanzees in 

 the Cincinnati collection. I have not had the 

 opportunity to study these apes themselves, as I 

 desired to do, since they are kept so closely con- 

 fined in a glass house, and forever under the eye 

 of their keeper, which conditions are not favor- 

 able to the best results. I am not prepared, there - 



108 



