380 ORIGINAL ARTICLES. 



frequently a bowed outline as they traverse the bundles of longitu- 

 dinal fibres, to form the roots of the spinal nerves. 



The white columns (Strange), Goll observes,* consist principally 

 of longitudinal fibres running parallel to each other, forming the 

 medium of communication of single portions of the cord with the 

 brain, and intersected by radiating bundles (Balkensfrahlen) of nerve- 

 fibre, which he describes as branching off like the veins of leaves 

 for the most part dichotomously, then again subdividing and con- 

 nected with each other. Coarser radiating bundles may be noticed 

 to divide the fibres into clusters of from twelve to fifteen districts of 

 radiations. Finer bundles subdivide these again into trapezoid or 

 rhomboid shaped clusters of the cut ends of the horizontal fibres. 

 These radiating bimdles are the medium of the passage of vessels and 

 nerve fibres from the centre to the surface. The periphery and 

 borders of the anterior fissures are covered with a layer of fine con- 

 nective tissue, which latter sends inwards processes connecting it 

 with the radiating bundles and the neuroglia. Grail also delineates, 

 in a somewhat exaggerated diagram, two wedge-shaped tracts of the 

 posterior white columns bounding iaternally the posterior middle line, 

 and on their outer sides being in contact with the posterior roots of 

 the nerves as they pass from the posterior horns of the grey sub- 

 stance. These tracts are not always distinctly marked. 



Kollikert distinguishes in the Avhite substance only horizontal and 

 longitudinal fibres, " running parallel to each other, never interlacing 

 nor constituting small fixsciculi. The number diminishes from above 

 dowTiwards, because they successively pass inwards towards the grey 

 substance, presenting the general characters of the central nerve- 

 fibres." The transverse fibres are found in those portions of the 

 columns which adjoin the horns, and at the points of entrance of the 

 nerves, and in the white commissui'e. 



Schroeder van der Kolk| describes the course of longitudinal 

 fibres in the anterior and posterior columns, and the passage of some 

 of these fibres into the transverse rays connected with the cells in 

 the grey matter. These contain, according to this author, separate 

 filaments for the several fimctions of sensation, motion, and reflex 

 action, and exist in greater numbers in the cervical and lumbar ex- 

 pansions, where the majority of reflex actions and movements are 

 excited and combined. 



A transparent section at right angles to the axis of the cord ex- 

 hibits very clearly the arrangement of the longitudinal and transverse 

 fibres. (Plate IX. fig. 1.) The latter are seen passing among the cut 

 ends of the former, and, as it were, majjping these out into circum- 

 scribed districts of bundles. Stilling has devoted one fasciculus of his 

 folio atlas to the delineation of the divers forms presented by these 

 blocks, or districts, as exhibited in opaque sections. By the employ- 

 ment of colouring matter (e. g. carmine or archil), the cut ends of the 



• P. 135. t Vol i. p. 408. X P. 56. 



