Just what evidence is there for this conception?  In the first place, there is the fascinating story of the origin of vertebrates from invertebrates of the sea scorpion or spider type.  Then there is a whole group of data which demonstrate that the primitive wishes which make up the content of a baby consciousness are determined, settled by states of relaxation or tension in different segments or areas of the vegetative apparatus.  According to this, the brain enters as only one of the characters in the play of consciousness.  It is just the organ of awareness by the organism of itself as an integer which must adjust itself to the specific condition within the disturbed vegetative apparatus.  Consequently the brain emerges not as the master tissue, but as merely the servant of the vegetative apparatus.

Consciousness is a circuit.  Swinging around in it are the wish-feelings generated by the vegetative dynamo.  From each viscus, from the stomach and intestine, from the kidneys and bladder, from the liver and spleen, from the blood-vessels, from all the glands of external and internal secretion, there flow along the vegetative nerves, to and from the brain, energies of various qualities and intensities.  All the members of the vegetative apparatus are more or less active, and so all our wishes are all more or less active.  All our working hours we are aware of hunger, satiety or indifference, of a desire to empty the intestine or bladder, or of a lack of necessity of doing so, of a state of tranquillity of the blood-vessels and sweat glands, or of a perturbation of them, of a varying tensity of even the muscles that are, as we say, under the control of the will, of the state, in fact, of all the elements of the vegetative complex.  The stream of feeling which constitutes the undertow of consciousness originates outside of the brain altogether, and is composed of currents arising from viscera, muscles, blood-vessels and glands.

Now the component currents are of different sizes and positions and variable degrees of warmth.  That is another way of saying that whether or not a current is to become the center of the stream, or to approach it, or whether it is to be hot, cold, or tepid, depends upon the degree of activity of the various parts of the vegetative apparatus.  A convenient name for this is tonus.  Tonus can be experimentally watched and measured.  Thus hunger, the most primitive of the wish-feelings, has been found to be simultaneous with certain characteristic contractions of the stomach.  Stop those contractions, and you stop the hunger.  The contractions begin slowly and weakly, and no awareness of them occurs in the mind.  As they grow stronger, consciousness becomes a sensation rather like an itch somewhere in the upper abdomen, and accompanied sometimes by a sense of general weakness.  The vegetative activity going on as a current almost on the outside of the stream of feeling has swelled and warmed, and so forced