them, the transformations which they undergo. But the single sciences are subordinated one to the other, and it is the province of one to explain the origin of the facts from which another has to start. Comparative philology may be powerless of itself to dispel the mystery which envelops the first beginnings of articulate speech; with the aid of the master-science of anthropology, however, the mystery ceases to be insoluble, and the origin and exercise of the faculty of speech become as little mysterious as the origin and exercise of the other faculties of civilized man.

We have already reviewed in the first chapter the various attempts that have been made in ancient and modern times to solve the riddle of language, and have seen how each fresh attempt has advanced the solution in a greater or less degree. False explanations have been gradually eliminated, approximately true ones have been corrected and defined. Here, as elsewhere, no single key will suffice to turn the lock; language is the product not of one cause, but of a combination of several. Grammar has grown out of gesture and gesticulation, words out of the imitation of natural sounds and the inarticulate cries uttered by men engaged in a common work, or else moved by common emotions of pleasure and pain. Language, in fact, is a social creation; we may term it if we like, a human invention, but we must remember that it is no deliberate invention of an individual genius, but the unconscious invention of a whole community. It is, as Professor Whitney has observed, as much an institution as is a body of unwritten laws; and like these it has been called forth by the needs of developing society.

Nowhere has the old proverb that "Necessity is the mother of invention" received a better illustration than in the history of speech; it was to satisfy the wants of daily life that the faculty of speech was first exercised, and the cries which were as natural to man as songs to birds, first adapted to the expression of articulate language. The clicks of the Bushman still survive to show us how the utterances of speechless man could be made to embody and convey thought. And the same process that slowly transformed the beast-like cries of our earliest ancestors into articulate sounds, slowly transformed the vague and embryonic thought enshrined in them into grammatical sentences. Like the beehive community to which modern research refers the first beginnings of society, the first essays at language were undifferentiated units, out of which the various parts of the sentence were eventually to come. The whole precedes its parts historically, if not logically, and it was only by setting sentence-word against sentence-word that the relations of grammar were determined, and means found in the existing material of speech for expressing them.

But in speaking of the origin of language we must be careful to distinguish between the origin of the faculty of speech and the origin of the exercise of it. So far as the origin of the exercise of it is concerned, it is not more difficult to explain than the origin of the exercise of our faculty of locomotion. We walk because we have the muscular power to do so, and this power must be exercised if we would satisfy our healthy desire to move the limbs and would supply the needs of our daily existence. The question as to origin of the faculty of speech falls

under the province of biology, and M. Broca speaking in the name of biology has endeavoured to answer it.' Whether the endeavour has been successful must be decided by future observation and experiment.

According to his researches the faculty of speech is localized in "a very circumscribed portion of the [two] cerebral hemispheres, and more especially of the left." These hemispheres, into which the brain or cerebrum is divided, are distinguished on their under side into three lobes the posterior, overlapping the cerebellum, on which the cerebrum partly rests, the middle, and the anterior, the two latter being separated from one another by the Sylvian fissure. Below this fissure is a triangular protuberance called the island of Reil, marked by small, short convolutions or gyri operti, which are among the first to be developed, and are surrounded by a large convolution forming the lips of the Sylvian fissure. It is on the upper edge of the Sylvian fissure, and opposite the island of Reil, that M. Broca places the seat of the faculty of speech in the posterior half of the third frontal convolutions of the right or left hemispheres. Aphasia, he finds, is invariably accompanied by lesion or disease of this portion of the brain. The lesion occurs in the left hemisphere in about nineteen out of twenty cases, and though the faculty of speech is sometimes not affected even by a serious lesion of the right hemisphere, it "has

1 See the "Bulletins de la Société anatomique," 1861, 63; 66 Bulletins de la Société de Chirurgie," 1864; "Bulletins de la Société d'Anthropologie de Paris,” 1861, 63, 65, 66; Proust: "Altérations de la Parole," in the "Bulletins de la Société d'Anthropologie de Paris," 1873; and "De l'Aphasie," in the " Archives générales de Médecine," 1872.

never been known to survive in the case of those whose autopsy has disclosed a deep lesion of the two convolutions" of the right and left hemispheres.

The greater importance of an injury to the left hemisphere seems due to the fact that the convolutions of this hemisphere develop at an earlier period than those of the right. To the same fact may also be ascribed the tendency of most persons from childhood to use the right rather than the left hand, the movements of the right-hand members of the body depending on the left hemisphere. Left-handedness is the exception, like the early development of the convolutions of the right hemisphere of the brain. So, too, the localization of the faculty of speech in the right hemisphere is equally the exception, language which is learnt in infancy naturally calling into exercise the most developed of the two portions of the brain. But like the left hand, the right hemisphere may in time acquire a certain control over language, and in most cases, accordingly, lesion of the left hemisphere produces merely aphasia, that is, inability to use words rightly, not inability to understand what is said by another. It is possible that the fluency and readiness of expression which distinguish certain speakers result from a simultaneous development of the frontal convolutions in both hemispheres of the brain.

The faculty of speech, whether exercised or unexercised, is the one mark of distinction between man and the brute. All other supposed marks of difference-physiological, intellectual, and moral-have successively disappeared under the microscope of modern science. But the prerogative of language still remains, and with it the

possession of conceptual thought and continuous reasoning. Though numberless instances may be brought forward which prove the possession of rudimentary reason and intelligence by the brute beasts, though instinct itself is but a kind of hereditary reason, thought in the true sense of the word is impossible without language of some kind. The power of forming concepts, of summing up generalizations under single heads which form the starting points of fresh generalizations, depends upon our power of expressing them in short-hand notes or symbols. like the words of articulate speech or the conventional signs of the mathematician. Language, it is true, is the embodiment of thought, but it is equally true that without language there can be no thought. The Tasmanian, with his poorly organized language, had no general terms; the New Caledonian is unable to understand such primary ideas as "to-morrow" and "yesterday," and the speechless child has not yet reached the level of intelligence displayed by the dog or the elephant.

But the child is capable of acquiring language, which the dog and the elephant are not, and this capability is sufficient to mark him off as a member of the human family. The faculty of speech may lie dormant and unexercised, but wherever it exists we have man. The deaf-mute, whose deafness has prevented him from learning to speak, or the mute whose diseased vocal organs refuse to utter the sounds he desires to form, are alike, men, able to share in the possession of language as soon as the physical difficulties which stand in their way are removed. Even the idiot or the patient suffering from aphasia cannot be compared with the parrot and other