ing life are semi-fluid. If we traced a nervefibre to the brain or spinal cord, we would find it starting from a process, or, as we call it, a pole, of a nerve-cell. When we trace it to a muscular fibre we find it loses the white substance of Schwann, and the axis-cylinder of the nerve-fibre pierces the sarcolemma, or sheath of the muscle-fibre, and ends in what
Fig. 50.—Various forms of nerve-cells. a, multipolar, from the gray matter of the spinal cord; b, d, bipolar, from ganglia on posterior roots of spinal nerves; c, g, from cerebellum; e, union of three cells; f, union of cells by processes.
is called an end-plate. The end-plates, seen in the diagrams (Figs. 51 and 52) vary in form and general appearance. Sometimes they consist of very slender fibres, produced by the splitting up of the axis-cylinder, and forming a network; but usually they take the appearance of irregularly shaped granular masses or discs.
As a rule, each muscle-fibre has a corre-
