The brain as an organ of mind . nection exist-ing between theseveral cells ofsensory groups andof motor groups,together with thekinds of communica-tion existing betweenthese two orders ofnerve units. 4. Between thecontiguous cells of amotor and perhapsalso of a sensorygroup, union isbrought about insome cases by means p 1 4- • 1 ^^^ 14.—Motor Nerve Cells connected by inter- OI a SnOrtj simple cellular processes (6, b), and giving origin to outgo- intCiCCllulctr lirOCeSS ^^ fibres (c, c, c, and a). 4. Multipolar cell contain- A ing much pigment around nucleus. Diagrammatic. such as we see repre
The brain as an organ of mind . nection exist-ing between theseveral cells ofsensory groups andof motor groups,together with thekinds of communica-tion existing betweenthese two orders ofnerve units. 4. Between thecontiguous cells of amotor and perhapsalso of a sensorygroup, union isbrought about insome cases by means p 1 4- • 1 ^^^ 14.—Motor Nerve Cells connected by inter- OI a SnOrtj simple cellular processes (6, b), and giving origin to outgo- intCiCCllulctr lirOCeSS ^^ fibres (c, c, c, and a). 4. Multipolar cell contain- A ing much pigment around nucleus. Diagrammatic. such as we see repre- (Vogt.)sented in figs. 1 and 14. But whether this is the most frequent means of union,or whether, in the majority of cases, especially amongstsensory groups, it is not rather by the inosculation of therootlets of ramifying processes (with the possible interme-diation of the neuroglia) we cannot at present say. Thereis reason to believe that both modes of union may exist. 5. The cells of a sensory group are united with the. 46 THE STRUCTURE OF cells of a motor group by one or other of these modes—though in regard to this point we have even less certainknowledge than concerning the last. Of the existenceof such connecting or * commissural fibres—^which areeither short or long according to the proximity or re-moteness of the two gi-oups ofcells—there can be no exists, however, withregard to the precise mode of theirconnection with the sensory nervecells on the one side and themotor on the other—whether ateither extremity they are continu-ous with undivided cell-processes,or break up and inosculate withramifying cell-processes. More room for doubt, therefore,exists in regard to the precisemodes in wdiich stimulus wavestraverse nerve centres, than con-cerning the manner in which theyimpinge upon or depart there-from. 6. In the sympathetic or vis-ceral ganglia of the Frog and otheranimals another kind of relationbetween fibres and cells has beenshown t
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