When the symbol is written with a numeral exponent, it indicates the degree of pitch. If there is no figure, the sound is such as would be made by the human voice in ordinary speech. The letter “X” indicates a repetition of the sound, and the numeral placed after it will show the number of times repeated, instead of the pitch. For example, we will write the sound (.), which is equivalent to long “O,” made in a normal tone; the same symbol written thus (.)^2 indicates that the sound is made with greater energy, and about five semitones higher. To write it thus, (.)^2X, indicates that the sound is five semitones above the normal pitch of the human voice and is once repeated. I shall not subject the reader to the tedium of elaborate details of the system here outlined. This brief _exposé_ of the method of representing the sounds of animals is sufficient to convey an idea of the means by which it is possible to write the sounds of all animals, so that the student of phonetics will recognize at once the character of the sound, even if he cannot reproduce it by natural means. It may be of interest to describe the character and use of some of the sounds uttered by the chimpanzee. The most frequent sound made by animals is that referring to food, and therefore it may claim the first attention. This word in the language of the chimpanzee begins with the short sound of the vowel “U,” which blends into a strong breathing sound of “H.” The lips are compressed at the sides, and the aperture of the mouth is nearly round. It is not difficult to imitate, and the ape readily understands it even when poorly made. By the method of writing above described it is expressed thus, (^I)`. A sound that is of frequent use among them is that used for calling. The vowel element is “[=U]” long, slightly sharpened. It merges into a distinct vanishing “W.” Expressed in symbols, it is (:)(. The food sound is often repeated two or three times in succession, but the call is rarely repeated, except at long intervals. One sound which is rather soft and musical is an expression of friendship or amity. It appears to soften in tone and lengthen in duration in a degree commensurate with the intensity of the sentiment. The vowel element is a long “U.” It blends into an aspirated “H.” It is fairly represented by the symbol (:)´. The most complex sound that I have so far heard made by them is the one elsewhere described as meaning “good.” They often use it in very much the same sense as man uses the expression “thanks,” or “thank you.” It is not probable that they use it as a polite term, yet the same idea is present.