An investigation of speech as a form of behavior, examined in the manner of the exact sciences by the direct application of statistical principles to the objective speech-phenomena. The findings of an extensive investigation of the stream of speech which is viewed as but a series of communicative gestures, presented in such a manner that they will be readily available not only to the professional linguist, but to any serious reader interested in linguistic phenomena. The author provides evidence for example, that the length of a word, far from being a random matter, is closely related to the frequency of its usage-the greater the frequency, the shorter the word. It can furthermore be shown that either from speech-sounds, or from roots and affixes, or from words or phrases, that the more complex any speech-element is phonetically, the less frequently it occurs.All the author's evidence points quite conclusively to the existence of a fundamental condition of equilibrium between the form and function of speech-habits, or speech-patterns in any language.