78 



THE ESSENTIALS OF HISTOLOGY 



In the ganglia the nerve-cells have a nucleated sheath (figs. 91- 

 93) which is continuous with the primitive sheath of the nerve-fibres 

 with which they are connected. In the spinal ganglia, and in many of 

 the ganglia at the roots of the cranial nerves, the cells are unipolar, 



FIG. 95. AXIS-CYLINDER 

 PROCESS OK NEKVK- 



CELL. 



x, x, portion of nerve- 

 cell ; u, axis-cylinder 

 process ; a', medullary 

 sheath. Highly magui- 

 fied. 



and the cell-process joins a traversing nerve-fibre by a T-shaped 

 junction (fig. 91). In the sympathetic ganglia they are multipolar. 

 The cells are disposed in aggregations of different size, separated by 

 the bundles of nerve-fibres which are traversing the ganglion (fig. 96). 



