rd of their sounds, I was able to discern as many as seven different
phones, all of which come within the scope of the human vocal organs. I
learned one of these sounds, and on a subsequent visit to Cincinnati I
succeeded in attracting the attention of the female, and eliciting from
her a response. She would come to the lattice door of the inner cage by
which I was standing, and when I would utter the sound she would press
her face against the door of the cage and answer it with a like sound.
The male, however, did not appear to notice it with any degree of
concern. I have no idea what the sound meant, and my opportunities have
not been such that I could translate it with the remotest degree of
certainty. [Sidenote: STUDIES IN TROPICAL AFRICA] These apes will be one
of the chief objects of my studies in tropical Africa, as I believe them
to possess a higher type of speech even than the gorilla. In this
opinion, which I reached from the study of other sounds and the types of
skull to which they belonged, I am not alone: Mr. Paul Du Chaillu, Mr.
E. J. Glave, and others who have seen both of these apes in their native
habitat, agree with me on this point. I am aware that this view is not
in strict accord with that of Professor Huxley, who assigns the gorilla
the highest place next to man in the order of Nature, and the chimpanzee
next below him. I shall not here attempt to discuss the question with so
high an authority, and I must confess that the vocal index is not yet so
well defined that it may be relied upon in classifying apes. One aim I
have in view is to study the gorilla and chimpanzee side by side in
their native wilds, and to record, if possible, the sounds of their
voices in a wild state. From the study of the sounds I have made, I feel
confident that all the vocal sounds made by these apes may be uttered by
the human vocal organs.

Some months ago I made a record of the voice of the great Anubis baboon,
in Philadelphia. I did not expect to find in him an elevated type of
speech; but my purpose was to compare it with other Simian sounds, to
see if I could not establish a series of steps in the quality of vocal
sounds which would coincide with certain other characters. I had found
by the study of certain cranial forms that certain vocal types conformed
to certain skulls, and were as much a conformation thereof as are the
cerebral hemispheres. I then believed, and have had no cause since to
recede from it, that the