FIG. 115. A, Bipolar nerve-cell with poles prolonged into medullated nerve-fibres. (Hey and 

 Retzius.) The entire cell is invested with the neurilenima. R R, nodes of Ranvier. 

 B, Portions of two nerve-fibres stained with osmic acid (from a young rabbit); diagrammatic, 

 425 diameters. (Schafer.) R R, nodes of Ranvier, with axis -cylinder passing through; 

 a, neurilemma ; a, nucleus and protoplasm lying between the neurilemma and the medullary 

 sheath. C, Medullated nerve-fibre treated with osmic acid. (Rey and Retzius.) E, node o'f 

 Ranvier; K, nucleus. The myelin of the medullary sheath is incompletely interrupted so as 

 to form conico-cylindrical segments. 



