THE NEUROGLIA  is the delicate connective

tissue which supports and binds together the nervous elements of the central nervous system . One part of it, which lines the central canal of the cord and ventricles of the brain, is formed of columnar cells, and is called ependyma, while the rest consists of small cells with numerous processes which sometimes branch and sometimes do not . These fibres interlace with one another to form a delicate felt-work which is unmixed with nervous elements on the surface of the grey matter of the brain (see BRAIN, figs . 7 and 15), though elsewhere it is inter-woven with them .