it is started; sometimes preparatory to and during the utterance there is a
tremulous motion about the muscles of the mouth. The hesitation increases,
and instead of a steady flow of modulated, articulate sounds, speech is
broken up into a succession of irregular, jerky, syllabic fragments,
without modulation, and often accompanied by a tremulous vibration of the
voice. Syllables are unconsciously dropped out, blurred, or run into one
another, or imperfectly uttered; especially is difficulty found with
consonants, particularly explosive sounds, b, p, m; again, linguals and
dentals are difficult to utter. Similar defects occur in written as in
vocal speech; the syllables and even the letters are disjointed; there is a
fine tremor in the writing, and inco-ordination in the movements of the
pen. Silent thoughts leave out syllables and words in the framing of
sentences; consequently they are not expressed by the hand. The ideation of
a written or spoken word is based upon the association of the component
syllables, and the difficulty arises primarily from the progressive
impairment of this function of association upon which spoken and written
language so largely depends. Examination of the brain in this disease
explains the cause of the speech trouble and the progressive dementia (loss
of mind) and paralysis with which it is associated. There is a wasting of
the cerebral hemispheres, especially of the frontal lobes, a portion of the
brain which, later on, we shall see is intimately associated with the
function of articulate speech.

THE CEREBRAL MECHANISM OF SPEECH AND SONG

Neither vocalisation nor articulation are essentially human. Many of the
lower animals, e.g. parrots, possess the power of articulate speech, and
birds can be taught to pipe tunes. The essential difference between the
articulate speech of the parrot and the human being is that the parrot
merely imitates sounds, it does not employ these articulate sounds to
express judgments; likewise there are imbecile human beings who,
parrot-like, repeat phrases which are meaningless. Articulate speech, even
when employed by a primitive savage, always expresses a judgment. Even in
the simple psychic process of recalling the name aroused by the sight of a
common object in daily use, and in affixing the verbal sign to that object,
a judgment is expressed. But that judgment is based upon innumerable
experiences primarily acquired through our special senses, wher