5 .-- The speech zone (after Collins).] _The Speech Zone._--Many interesting facts of the relation of body and mind have come to light in connection with the speech functions.
Speech is complex, both on the psychological and also on the physiological side, and easily deranged in ways that take on such remarkable variety that they are a source of very fruitful indications to the inquirer.

It is now proved that speech is not a faculty, a single definite capacity which a man either has or has not.

It is rather a complex thing resulting from the combined action of many brain centres, and, on the mental side, of many so-called faculties, or functions.

In order to speak a man normally requires what is called a "zone" in his brain, occupying a large portion of the outside lateral region (see Fig.

5).