5. When venous blood, instead of arterial, is sent through the blood-vessel of a muscle, the irritability speedily disappears, and unless fresh oxygen is administered the muscle soon ceases to act and dies.
6. The oxidation power is determined by the tissue and by the tissue only.
7. All the available evidence goes to show that oxidation takes place in all the tissues and not in the adjoining blood.
The master tissues of the body are the muscular and nervous tissues. All other tissues may be regarded as the servants to these.
These tissues are the all-important tissues in the body. The muscular tissues constitute and carry out the power, force, or energy of the body. They set the body in motion. They do the work. They regulate the delicate movements of the organs of special sense or function, as the eye, the ear, the tongue, the nose, larynx, thorax, abdomen; and fighting, defending, building, destroying, labor and mechanical skill of whatever nature, depend on them. Of exercise, sport, pain and pleasure, sensation, emotion, expression of the face, in fact all in all in every act of life, the muscles, the voluntary muscles, must perform the work.
They are called the muscles of Animal life. They are Voluntary; they may be set in action at will.
For guidance, control, coördination, sensation, and motion, the muscular tissues are dependent on the nervous tissues.
It is not difficult to understand, I think, as will be explained later on, that all muscular movements are perfectly natural, purely physical and mechanical.
The nervous tissue will be a little more difficult to comprehend, for causes that are reasonable and plain.
All animals are provided with two distinct sets of organs: 1. The master tissues, the nervous and muscular tissues, the voluntary muscular tissues, which are the organs of animal life, the voluntary, the active organs that do the work, consume the food, and throw off the waste material; and 2. The servants to these, the involuntary tissues, the organs of organic life that prepare the food, carry it to the master tissues, and bring away the waste material.