Concurrent with the variations described, the longitudinal, vertical, and transverse axes of the brain also change their proportion in a like degree. The angles formed by the plane of the vocal cords with the axis of the larynx undergo a corresponding change. A just deduction from these facts is, that the gnathic index ADE is a true vocal index.
This rough outline of the law of cranial projection does not purport to be a full treatment of the many lines and angles correlated to the powers of speech, but the suggestions may lead the craniologist into new fields of thought.
CHAPTER II
Early Impression—What is Speech—First Efforts—The Phonograph—The First Record of Monkey Speech—Monkey Words—Phonetics—Human Speech and Monkey Speech
Among the blue hills and crystal waters of the Appalachian Mountains, remote from the artificialities of the great cities, the conditions of life under which I grew up were more primitive and less complex than they are in the busy centers of vast population. There nature was the earliest teacher of my childhood, and domestic animals were among my first companions. Among such environments my youth was passed, and among them I first conceived the idea that animals talk. As a child, I believed that all animals of the same kind could understand each other, and I recall many instances in which they really did so.
My elders said that animals could communicate with each other, but denied that they could talk. As a boy, I could not forego the belief that the sounds they used were speech; and I still ask: In what respect are they not speech? This question leads us to ask another.
What is speech? Any oral sound, voluntarily made, for the purpose of conveying a preconceived idea from the mind of the speaker to the mind of another, is speech. Any oral sound so made and so discharging this function in the animal economy is speech. It is true that the vocabularies of animals, when compared with those of man, are very limited; but the former are none the less real. The conception in the mind of an animal may not be so vivid as it is in the human mind, but the same conception is not always equally clear in two human minds. The fact of its being vague does not lessen its reality.
Expression is the materialized form of thought, and speech is one mode of expression. Every animal is capable of expressing any thought that he is capable of conceiving, and such expression will be found to be as distinct as the thought which it expresses. It is inconsistent with every view of nature to suppose that any creature is endowed with the faculty of thought and forbidden the means of expressing it.
It is true that there are some oral sounds which express emotion—such as pain or pleasure. These may not properly be called speech, although from them we may infer the state of mind attending them; but while they are not truly speech, they appear to be the cytula from which speech is developed. While emotions are not voluntary, they do not exist apart from mind. They are produced by external causes, and the line of demarcation which separates them from more definite forms of thought is a vague and wavering one. Thought may be involuntary, but expression arises from desire, and this is the sole motive of speech.
It is not the purpose of this work to discuss the problems of psychology, except to state the grounds upon which we base the claim that animals possess the faculty of speech; but this is intended as a record of observed facts and from them the psychologist may make his own deductions.