Observations on the Structure and Distribution of Striped and Unstriped Muscle in the Animal Kingdom, and a Theory of Muscular Contraction

Striped muscle has long been known to occur widely distributed in the animal kingdom, but the details of the structure of the striped muscle-cell have been the subject of much controversy. Various descriptions have been given, widely differing from one another, and none of them affording a satisfactory basis of comparison with other cells. The demonstration of an intracellular network in the muscle-fibre by several recent observers appears to afford the most rational clue to its structure, for it not only explains all the appearances seen in the muscle-fibre, including those seen with polarised light in the living fibre by Brücke, but it also renders possible a comparison with other cells, and shows that a muscle-fibre is to be regarded as of essentially the same structure as an ordinary cell, and must not be considered as an enigmatical structure, the details of which do not correspond to those of any other cell in the animal economy.