to a lack of co-ordination
between the brain and the muscles of speech. In other words, the
harmony between the brain and the speech organs which normally result
in smooth working and perfect speech has been interrupted. The brain
impulses are no longer properly transmitted to and executed by the
muscles of speech.

This failure to transmit properly brain messages or this lack of
co-ordination may take one of two forms: it may result in an
UNDER-innervation of the organs of speech, which results in loose,
uncontrolled repetitions of a word, sound or syllable, or it may take
the form of an overinnervation of the vocal organ with the result that
it is so intensely contracted as to be entirely closed, causing the
"sticking" or inability to pronounce even a sound, so common to the
stammerer.

Suppose that you try to say the word "tray." Do not articulate the
sounds. Merely make the initial effort to say it. What happens? Simply
this: The tip of the tongue comes in contact with the upper front teeth
at their base and as you progress in your attempt to say "t," the
tongue flattens itself against the roof of the mouth, moving from the
tip of the tongue toward its base. If you are a stammerer, you will
probably find in endeavoring to say this word, that your vocal organs
fail to respond quickly and correctly to the set of brain messages
which should result in the proper enunciation of the word "tray." Your
tongue clings to the roof of your mouth, your mouth remains open, you
suffer a rush of blood to the face, due to your powerful and
unsuccessful effort to articulate, and the word refuses to be spoken.

Now, in order to dissociate "lack of co-ordination," from stammering
and to get an idea of its real nature, let us imagine an experiment
which can be conducted by any one, whether they stammer or not.

You see on the table before you a pencil. You want to write and
consequently you want to pick up the pencil. Therefore, your brain
sends a message to your thumb and forefinger, saying, "Pick up the
pencil." Your brain does not, of course, express that command in words,
but sends a brain impulse based upon the kinaesthetic or motor image of
the muscular action necessary to accomplish that act. But for our
purpose in this experiment, we can assume that the brain sends the
message in terms which, if interpreted in words, would be "pick up the
pencil." Suppose that when that brain message reaches your thumb and
forefinger, inste