136 COSMIC PniLOSOrilT. [PT. II. 



Between these fibres and cells there are differences of mole- 

 cular structure implying differences in molecular activity. 

 While the matter composing a cell is built up in enormously 

 complex aggregates of molecules, wholly unshielded from 

 external disturbance, the nerve-matter of a fibre is protected 

 throughout its entire length by a membranous sheath. And 

 while it is probable that the action going on in a cell consists 

 in the continual fall of unstably arranged molecules into a state 

 of more stable equilibrium, from which a fresh rush, of blood is 

 continually raising them to their former unstable state ; it is 

 probable that the action going on in a fibre consists in the 

 successive isomeric transformations and retransformations of 

 the systems of molecules which make up the fibre. These 

 conclusions are quite probable, though not proven. But it is 

 entirely proved that a cell is a place where nervous energy is 

 liberated, while a fibre is a path along which nervous energy 

 is transmitted. 



Bearing all this in mind, it appears that the cerebrum and 

 cerebellum are places where countless centres are constantly 

 liberating nervous energy, and where this liberated energy is 

 continually flowing along definite channels and from one centre 

 to another. But to make the statement complete, we should 

 add that much of the liberated energy is drafted off along 

 centrifugal fibres into the corpora striata, whence it flows into 

 the medulla and spinal centres, and is thus diffused over the 

 body. Omitting the further consideration of these circum- 

 stances, let us inquire into the meaning of this unceasing 

 interchange of molecular motion between the innumerable 

 cells crowded together in the cerebrum and cerebellum, 

 la other words, what are the functions of these supreme 

 ganglia ? 



That their functions are not in any degree the direct co- 

 ordination of sensations and movements, would appear from 

 the fact that these direct coordinations are already made in 

 the spinal cord and in the medulla. All the muscular adjust- 



