324 BIOLOGICAL PHYSICS 



or become, functionally active, and capable of performing 

 good work, both quantitatively, and qualitatively, but, 

 more especially, after awaking ; hence, it is frequently 

 found, that a problem, which has been engaging much 

 attention previously, is revealed in "early waking" 

 thought, displaying itself almost spontaneously, in full 

 proportions, and true perspective, without apparent mental 

 effort. 



Such is the cerebral habitat or, " home, of the ego" 

 and such is some of the work done therein, by the 

 true psychic neuronal textures, constituting the debat- 

 able cerebral region, dividing the two great areas of 

 sensory, and motor, neural activity, in which are dis- 

 played the phenomena of afferent, and efferent, inner- 

 vation, and affording a buffer region of neutrality, and 

 calm, in which can be displayed the processes of 

 thought, intelligence, and will, with all that characterises 

 the mental outlook of the genus homo, as distinguished 

 from his zoological, neighbours, and friends. 



Neurologists hold, that both afferent, and efferent 

 neurons, are histologically produced, and evolved, once 

 for all, non-renewal following on their destruction ; and 

 the truth of the opinion becomes abundantly evident, 

 when we consider that both nervatures correspond, in 

 number, and extent, of terminal extensions, with the 

 extent of sensory surface, and the number of muscular 

 fibres, to be innervated, by the respective, sensory, and 

 motor, nervatures. Whether the same doctrine may 

 apply to the intermediate, or psychic, neurons, it would 

 be highly interesting, and instructive, to know, but, 

 here, the structures to be examined, are so minute, and 

 complex, in their distribution, that it may easily be 

 that the most elaborate research may fail to reveal this ; 

 however, we are warranted in saying, that, it is quite 

 possible, there may be a difference in their histogenesis, 

 which will allow of a growth, and increase, in the intelli- 

 gence, during adult life, or after the growth of the body 

 has ceased, and the afferent, and efferent, nervatures have 

 reached their climax, or limit, of development, by increase 

 in growth, and extent, of their dendritic, and axonal 

 processes, if not of their actual numbers. 



