THE CENTRAL NERVOUS SYSTEM. 



305 



evidently come from cells of the anterior horns lower down. 

 Some of the fibres, passing back from the anterior horns to join 

 the root, are seen to arise directly from the motor cells. 



In taking leave of the cord, the introduction of a diagram 1 

 showing its regional anatomy, looked at from a physiological 

 standpoint, is deemed ad- 

 vantageous. It will enable p 

 the microscopist to properly 

 record localized lesions. 



In studying the spinal 

 cord by means of horizon- 

 tal transverse sections, it is 

 of the utmost importance, 

 particularly in pathological 

 cases, to know which is the 

 right or left side, and whe- 

 ther one is looking at the 

 upper or under surface of a 

 section. Of so much impor- 

 tance is this knowledge, 

 that some means must be 

 employed to acquire it. 



One of the best means is a method devised by Dr. E. C. 

 Seguin, and published in the translator's note appended to 

 Schultze' s article on the spinal cord, in the American translation 

 of Strieker's " Histology," p. 647. He there recommends, be- 

 fore placing the segment of the cord in the microtome, that a 

 slight longitudinal incision be made in the right lateral column. 

 By this means all the sections have a nick in the right lateral 

 column, and can easily be placed. This method, however, has 

 many drawbacks. One is that it is a process easily forgotten 

 during the manipulations. Another more serious drawback is 

 the fact that, make the incision slight as you can, the resulting 

 nick often causes extensive fissures and crumbling of the lateral 

 column or whole section, especially in pathological or over- 

 hardened specimens. 



The requirements by the new method are two : 1st, the 

 sections must be nearly horizontal ; and 2d, they must be suf- 



FIG. 130. Diagram of transverse section of the 

 spinal cord : A, anterior median fissure ; P, posterior 

 median septum ; 1, columns of Goll ; 2, columns of 

 Burdach ; 8, direct cerebellar column ; 4, crossed pyra- 

 midal column ; 5. lateral column ; 6, anterior funda- 

 mental column ; 7, direct pyramidal column ; 8, pos- 

 terior gray horns ; 9, anterior gray horns ; stippled 

 part, gray matter ; shaded part, sesthesodio system ; 

 unshaded part, kinesodic system. 



1 Dr. E. C. Seguin : Lectures on Localization, in N. Y. Medical Record, April 27, 

 1878, p. 323. 



