ON THE NEUROGLIA 287 



axons, with ultimate terminal incorporation with the 

 musculo-skeletal, and dermal, tissues, and final, disintegra- 

 tion, and elimination. 



If we accept these views, can we wonder at the mental 

 strength so often maintained, when bodily weakness has 

 taken possession of the organism ? We unreservedly say, 

 we cannot, inasmuch, as when the neuro-musculo-dynamic 

 machinery has been almost entirely switched off from the 

 sensory, and motor, centres, we are logically and physio- 

 logically, compelled to believe that the mind can, for long 

 periods subsist, more or less completely, on the large 

 passive reserve, stored up within the great materio- 

 dynamic repository of still unused neuroglial plasma, and 

 energy, and that intellectual cerebration can, so, be con- 

 tinued, until the stage of absolute dynamic exhaustion has 

 been reached when, as in long-continued fever, entire 

 unconsciousness may set in, and reign, until the great 

 sympathetic nervous system determines, whether it is 

 capable of still maintaining life, and of renewing the 

 regime of systemic innervation, and conscious cerebration. 



As the meso- and hypo-dermal tissues extract, and 

 metabolise, their nutritive supplies, directly, or indirectly, 

 from the all-pervading blood streams, so do the ecto- 

 dermal tissues extract, and metabolise, theirs from the 

 neuroglial matrix, the one being as essential, as the other, 

 in rendering possible, the performance of their respective 

 functional roles, and systemic work. These two great 

 passive elements, the blood, and the glia, representing, 

 respectively, the storehouses, so to speak, Irom which the 

 two great nervatures of the body draw their materio- 

 dynamic supplies, and convert them into work, and 

 unutilisable residuum. 



The pia mater^ on which the neuroglia is dependent, 

 for the peculiar nutritive material, on which the neurons 

 live, and grow, and for the supply of that peculiar lymph, 

 which encircles, and inter-penetrates, the sponge-like struc- 

 ture of the entire systemic nervous system, finds, prepared 

 for the scene of its anabolic work, a superlatively finely 

 meshed basic (see Fig. 119) texture, or feltage, of cellulo- 

 fibrous formation, amid the interstices of which it deposits 

 that peculiar nutritive material, or glia, and through whose 



