2136. The heart is the prototype of the muscular system. All muscles must be a metatype of the heart.
2137. The muscle is hollow. It is a cyst.
2138. The muscular system is a manifold and serial juxtaposition of fibrous cysts or of hearts. In this respect the muscle has been formed in a corresponding manner to bone. Both are rows of cysts.
2139. But the muscle, as being the external fibrous tunic, is the enveloping or external cyst.
2140. In idea, the muscle can only directly envelop the bones, and not the other parts, for it ranks upon the same grade of development with the bone; it is the arterio-fibrous wall, while the bone is the internal arterial wall.
2141. Bone and flesh stand in antagonism like air and earth. The muscle is that which is polarizing—moving, the bone what is polarized, moved. The muscle is heart, the bone the moved blood. Bone and muscle are related as that which is contained and what is containing. The muscle is the wall of the cyst, the bone, the fluid which has been secreted from it and rigidified.
2142. As therefore the muscle is an individual cyst, a heart, which cannot invest the whole body like a single large cyst, so also must the muscular contents be only a discrete cyst. The uninterrupted character of the bones depends therefore upon that of the muscles, and the latter upon the meaning of the heart.
2143. A physiological rationale of the joints is accordingly afforded in the heart.
2144. A bone is a rigidified, ossified heart; the osseous system is a series of mutually dependent, alternately ossified and non-ossified (arteriose and venous) hearts.
2145. The muscular cyst includes the soft bone, or the joint.