OUR TELEPHONE EXCHANGE AND ITS CABLES The Brain.

We are exceedingly proud of our brain and inclined to regard it as the most important part of our body.

So it is, in a sense; for it is the part which, through its connecting wires, called the _nerves_, ties together all the widely separated organs and regions in our body, and helps them to work in harmony with one another.

We speak of it as the master and controller of the body; but this is only partially true.
The brain is not so much the President of our Cell Republic as a great central telephone exchange, where messages from all over the body are received, sifted, and transmitted in more or less modified form, to other parts of the body.

Three-fourths of the work of the brain consists in acting as "middle-man," or transmitter, of messages from one part of the body to another.