Studies in the wave-mechanics of muscle form and function IV. Striated muscle and tendon are in biophysical continuity as the vibrating and non-vibrating parts, respectively, of the same stretched structure of protoplasm. Muscle and tendon are continuous by either a sharp or a gradual transition. Anatomic dampers of protoplasmic lateral expansion are related to tendon V. The experimental biophysics of the replacement of muscle by fibrous. tissue, cartilage or bone by the dampening of the movement of the lateral expansion of muscle by aluminum rings