31 8 NERVE-CELLS. 



of pigment granules (fig. 372, b). The colour is deeper in adult age than in 

 infancy. 



Every nerve-cell has one or more processes, and the cells are often named 

 according to the number of processes they possess, uni-, bi-, and multi-polar ; terms 

 not perhaps well chosen, but rendered current by use. A fibrillation similar to that 

 in the axis-cylinder of a nerve-fibre is visible in the cell-processes, and it may also 

 be traced passing from them into the body of the cell and even through this from 



Fig. 368. Two NERVE-CELLS FROM THE SPINAL CORD OF THE ox, ISOLATED AFTER MACERATION IN 



VERY DILUTE CHROMIC ACID. MAGNIFIED 175 DIAMETERS. (E. A. S. ) 



Each cell has a well-defined, clear, round nucleus, and a large nucleolus. The cell-processes are 

 seen to be finely fibrillated, the fibrils passing from one process into another through the body of the cell, 

 a, axis-cylinder process broken a short distance from the cell. 



one process into another (fig. 368). Some affirm that they have been able to trace 

 a connection of these fibrils with the nucleus of the cell, but this is at present 

 doubtful. 



Nerve-cells which are entirely destitute of processes have sometimes been described. 

 It is possible that such may exist, but there is always a probability that these may 



