The sounds which monkeys make are voluntary, deliberate, and articulate. They are always addressed to some certain individual with the evident purpose of having them understood. The monkey indicates by his own acts and the manner of delivery that he is conscious of the meaning which he desires to convey through the medium of the sounds. They wait for and expect an answer, and if they do not receive one they frequently repeat the sounds. They usually look at the person addressed, and do not utter these sounds when alone or as a mere pastime, but only at such times as some one is present to hear them, either some person or another monkey. They understand the sounds made by other monkeys of their own kind, and usually respond to them with a like sound. They understand these sounds when imitated by a human being, by a whistle, a phonograph, or other mechanical devices, and this indicates that they are guided by the sounds alone, and not by any signs, gestures, or psychic influence. The same sound is interpreted to mean the same thing, and obeyed in the same manner by different monkeys of the same species. Different sounds are accompanied by different gestures, and produce different results under the same conditions. They make their sounds with the vocal organs, and modulate them with the teeth, tongue and lips, in the same manner that man controls his vocal sounds. The fundamental sounds appear to be pure vowels, but faint traces of consonants are found in many words, especially those of low pitch; and since I have been able to develop certain consonant sounds from a vowel basis, the conclusion forces itself upon me that the consonant elements of human speech are developed from a vowel basis. This opinion is further confirmed by the fact that the sounds produced by the types of the animal kingdom lower than the monkey, appear to be more like the sounds of pipe instruments; and as we rise in the scale, the vocal organs appear to become somewhat more complex, and capable of varying these sounds so as to give the effect of consonants, which very much extends the vocal scope. The present state of the speech of monkeys appears to have been reached by development from a lower form. [Sidenote: EACH RACE HAS ITS PECULIAR TONGUE] Each race or kind of monkey has its own peculiar tongue, slightly shaded into dialects, and the radical sounds do not appear to have the same meaning in different tongues. The phonetic character of their speech is equally as high as that of children in a like state of mental development; and seems to obey the same laws of phonetic growth, change, and decay as human speech. It appears to me that their speech is capable of communicating the ideas that they are capable of conceiving, and, measured by their mental, moral, and social status, is as well developed as the speech of man, measured by the same units. Strange monkeys of the same species seem to understand each other at sight, whereas two monkeys