CHAP. II.] A NERVOUS SYSTEM. 37 



cesses/ which are either much branched (fig. 12) 

 (ramifying processes) or simple. It is by means of these 

 different kinds of processes that nerve cells are united 

 to the central extremities of the nerve fibres and to one 

 another. It is worthy of note that the substance, both of 

 the nerve cell and of its processes, when examined under 

 high magnifying powers can often be seen to be dis- 

 tinctly fibrillated in the same manner as the ' axis band ' 

 of a nerve fibre, with which, or with the ramifications of 

 which, some of these processes are continuous. 



If the fibrillations of the axis band, and of the nerve 

 process into which it may be continued, correspond with 

 functionally if not structurally distinct fibrils that is, with 

 separate paths for stimulus waves so, in all probability, 

 the fibrillations of the nerve cells will indicate as many 

 distinct paths of stimulus waves through them in different 

 directions. The appearances presented by the cells are 

 quite consistent with this view (fig. 8). Fibrillations, for 

 instance, can be seen passing from one nerve process 

 in a curved direction through the body of the cell and into 

 another process ; whilst others in the same process can be 

 followed through the cell in quite different directions. 

 There is no difficulty in supposing that many nerve currents 

 may pass through one of these compound nerve fibres, 

 just as many electric currents might pass simultaneously 

 through a single telegraphic or telephonic wire. 



These fibrillations of the nerve cell are probably sequen- 

 tial to, and gradually differentiated in the course of, its 

 functional activity. It is not unreasonable to expect that 

 there would be a gradual marking out of the paths of 

 habitual nerve currents, through the previously structure- 

 less though slightly granular substance of the nerve cell, 

 during their passage from fibre to cell and fr<?m one of 

 these bodies to another. 



