: SPINAL r<n;i>. 



in the inferior, and on.- in the siijn rior irn-y eornu. 

 respond t what Stilling has named the ///(/. 



11s, the xiiprrtor vesicular column 

 i >f (Yi//-/.v, or dorsal nucleus of Slillinj, in 

 id at the point where the grey com- 

 missure joins the eornua. The nerve tubes 

 (or tubules) affect longitudinal, transversal, 

 oblique, and vertical directions. 



They bring the cells of one lateral 

 moiety of the medulla into communication 

 with : 1, The tubes of the white substance ; 

 2, Each other ; 3, The cells of the opposite 

 moiety, by passing into the commissures ; 

 4, The tubes of the white substance of the op- 

 moiety, by following the same course. 



The neuroglia and nerve-tubes consti- 

 tute the white substance, which is decom- 

 posed, as we know, into three cords. All 

 the tubes of this substance do not ascend 

 to the brain, as was believed for a long time ; 

 the opinion that the tubes of the spinal 

 s formed the medulla and extended to 

 the brain, has been abandoned since Volk- 

 mann measured, comparatively, the section 

 of all these nerves and that of the nervous 

 spinal-axis. 



(Volkmann has established the fact, that 

 the size of the medulla corresponds with the 

 number of nerve-tubes given off at any point. 

 1 1 < reives the weight of four segments, each 

 nches in length, from the spinal cord 

 of the Horse, and the relative extent of the 

 grey matter in square lines; these are as 

 follows : 



The columns cor- 

 j nerve*. A fourth 



'.--'0. 



Grtlns. 



From below 2nl Spinal Nerve. 'J!9 



th 

 .. intii ,. 163 



, 3Utll , -J-l 



Area 



. , , V 



M -.f. 

 13 

 28 

 II 

 25 



Area 



of White 

 Matter. 



109 



14] 

 9 



121) 



Iii thewhite-substane, the tub, < are W InN ,, iril]N u . SK( . TION TIIII( ,,,, 1I 



gitudinal, oblique, or transversal ; the Utter C1 1: \ , iNAI 



arise from the cells of the grey substance, on:i> <>i u. 



and represent the roots of the nerves AC, Inferior whit.- columns; AC', Por- 



merging either by the superior or inferior <'" ^'"in- tli..- arrangement of 



collateral fissure. th. longitudinal fibre*; i-c Po- 



, ., . , tenor white column.s; <;, <lr.-v 



The tubes of the anterior cords pass to .uuunce bet ween th,. n ,(th.. 



being omiM.-l to avoid obscuring 



the course of the fibres); A, Anterior roots of the nerves; i% Posterior root*, consisting 

 of thr.;e kinds: the tirst, d, crossing the posterior columns hri/.ont:iily. and tm-n pan- 

 ing obliquely downwards, across the grey substance, into the- :mt-rior columns; the 

 second, /', ir.u.-r in-,' the posterior columns horizontally, and then losing then 

 in the irivy Mili>t:im-- : thu third, .-, for the in..,; put .itiuiuuw with the 



itndinal fibres of the posterior column; all. or nearly all, ultimately entering the 

 substance. 



