ANIMAL AND VEGETABLE 207 



branch circuits, collaterals, or dendrons (corresponding to 

 our wires of the outer globe) which terminate in arborisa- 

 tions or end-organs, connecting, interlacing, or inter- 

 mingling with other nerve-cells, of which they are anato- 

 mically independent. These other cells and arborisations 

 act, as I have endeavoured to show, as condensers in 

 changing the sign of current or impulse, and, as I have 

 suggested, any variation of tension may be brought about 

 by varying the area of the condenser-plates, discs, or 

 points, or conducting cell areas. 



In the typical multipolar cells of the spinal cord, as 

 shown by Max Schultze, only one process becomes the 

 axis-cylinder of a nerve-fibre, the others breaking up into 

 arborisations of fibrils which can be traced into the axon 

 and the other branches of the cell. " Between the fibrils 

 the protoplasm of the cell contains a number of angular or 

 spindle-shaped masses . . . known as Nissl's granules " 

 (see p. 189). " These nerve-cells often contain . . . granules 

 of pigment, usually yellow, the nature of which has not 

 been determined." As a matter of possibility, the yellow 

 pigment may be an insulating substance of the nature of 

 elastin, but as to this I am not, in the absence of any 

 definite information as to its chemical composition, able to 

 offer an opinion. 



We may now compare a multipolar ganglion cell as 

 illustrated physiologically with the artificial contrivance 

 before mentioned. (Figs. 112, 113.) 



Supposing an efferent impulse to be conveyed to the 

 inner globe, as shown in the electrical diagram, all the 

 discharge impulses would be afferent, and, as I before 

 remarked, the cell would not be multipolar. A condenser 

 of suitable capacity inserted between any one or more of 

 the terminals c, d, e, g, h, i, j, k, would retransform the 

 impulse from afferent to efferent, and either raise or further 

 lower the tension in accordance with its surface area, 



