The cellular texture is very abundant in the muscular system; I know of no system that has a greater proportion of it. This texture forms a very evident covering around each muscle. This covering is most commonly loose, filled with fat, easily distended with air in emphysema and serum in anasarca. At other times it is more dense, compact and really arranged like a membrane. Such, for example, is the case with that which covers the great oblique muscle of the abdomen, and the dissection of which on this account, students at first find very difficult. The other abdominal muscles, the trapezius, the serratus major and the great dorsal exhibit also this arrangement. We might say that in this way nature compensated for the aponeuroses, which are wanting on the broad muscles of the trunk. Besides, this covering has only a membranous appearance; it has nothing of its organization, it disappears in the infiltration in which all the true membranes remain. Besides this general covering of the muscle, each fasciculus has a less covering, each fibre a still less one, and each smaller one a real though almost insensible sheath. We can then represent the cellular texture of the muscles as forming a series of coverings successively decreasing. These coverings favour the motion of the fibres which they separate, either by the serum of the cells, or by the fat they contain, both fluids, by lubricating, allow them to slip more easily upon each other. Frequently between these fibres, the cellular texture appears to form a kind of cross pieces which go at right angles. We see this arrangement especially in the proper extensor of the great toe, and in the common extensor, the fleshy fasciculi of which are broad and delicate when distended. In most of the thick muscles nothing similar is observed. The quantity of intermuscular cellular texture is remarkably variable. In general, in all the broad muscles and in all the large, long muscles, it is very abundant. It is less in proportion between the fibres of those of the vertebral canals. Back of the neck, the splenii, complexi, &c. have less of it than many others, especially in the spaces that separate them. Sometimes very considerable cellular elongations are found in the middle of the muscles, and seem to divide them into two; such is that which separates the clavicular portion of the great pectoral; this has even sometimes embarrassed anatomists as to the division of these organs.