During my researches I have learned ten words of the speech of this ape, so that I can understand them and make myself understood by them. In tone, pitch, and modulation most of the sounds are within the compass of the human voice. Two of them are much greater in volume than it is possible for the human lungs to reach, and one of them rises to a pitch more than an octave higher than a human voice of middle pitch. These two sounds are audible at a great distance, but they do not properly fall within the limits of speech. The vocal organs of the chimpanzee resemble those of man as closely as other physical features have been shown to resemble. They differ slightly in one respect that is worthy of notice. Just above the opening called the glottis (which is the opening between the vocal cords) are two small sacs or ventricles. In the ape these are larger and more flexible than in man. In the act of speaking they are inflated by the air passing out of the lungs into the long tube called the larynx. The function of these ventricles is to control and modify the sound by increasing or decreasing the pressure of the air that is jetted through the tube. They serve at the same time as a reservoir and as a gauge. In the louder sounds uttered by the chimpanzee these ventricles greatly distend. This intensifies the voice or increases its volume. It is partly due to these little sacs that the ape is able to make such a loud and piercing scream. But the pitch and volume of his voice cannot be alone due to this cause, for the gorilla (in which these ventricles are much smaller) can make a vastly louder sound. We may be mistaken, however, about the sound commonly ascribed to him. Although the sounds made by the chimpanzee can be imitated by the human voice, they cannot be expressed or represented by any system of phonetic symbols in use among men. Alphabets have been deduced from pictographs, and the conventional symbol that is used to represent a given sound has no reference to the organs of speech that produced it. The few rigid lines that have survived and that now form the alphabets are within themselves meaningless, but they have been so long used to represent the elementary sounds of speech that it would be difficult to supplant them with others. As no literal formula can be made to represent the phonetic elements of the speech of chimpanzees, I have taken a new step in the art of writing. I suggest a system of symbols which is rational in method and simple in device. The organs of speech always act in harmony. A certain movement of the lips is always attended by a certain movement of the internal organs of speech. This is true of the ape as well as of man. In order to utter the same sounds, each would employ the same organs and use them in the same manner.