ANIMAL AND VEGETABLE 171 



Furthermore, we will draw D upon a larger scale, as I 

 imagine it to be (see Fig. 91). 



We can have no doubt that c, c, c are conductors 

 because they transmit impulses ; d, d, d must be dielec- 

 trical in character, as they are designed to conserve energy 

 in the axon, and there is reason for the belief that both 

 neuroglia and connective tissue are non-conducting sub- 

 stances. 



A condenser, as used in telegraphy, is conventionally 

 shown in illustration, and the 



analogy, if we pursue it, is ~ ^j- *- 



rather remarkable. In the 



rig. wlA. 



figure only the conduct- 

 ing plates are shown. Let us insert the dielectric, and 

 the sy nap tic connection appears to be a condenser of large 

 surface-area, but possibly, by reason of the points or pro- 

 jections, of comparatively high tension. 



Fig. 92. 



According to Schafer, the " arborisations from different 

 cells may interlace with one another (as in the olfactory 

 glomeruli, in the retina, and in the sympathetic ganglia), 

 or a terminal arborisation from one cell may embrace the 

 body or the cell-processes of another cell ; as with the cells 

 of the spinal cord and the cells of the trapezoid nucleus of 

 the pons Varolii, and in many other places. The term 

 neuro-synapse may be applied to these modes of junction. 

 By them nerve-cells are linked together into long chains 

 of neurons, the physiological path being uninterrupted, 

 although the anatomical path is believed to be interrupted 

 at the synapses. " 



