886 THE FEATURES OF DIFFERENT REGIONS. [BOOK in. 



574. The white matter as we have seen increases in sectional 

 area with considerable regularity from below upwards. If instead 

 of a diagram of the increase of the whole white matter, we 

 construct in a similar way diagrams of the anterior, posterior and 



\ 



V IV III II I V IV III II 



X IX VIII VII VI V IV III 



I VIII VII VI tf IV III II 



FIG. 105. DIAGRAM SHEWING THE VARIATIONS IN THE SECTIONAL AREA OF THE 

 LATERAL COLUMNS OF THE SPINAL CORD, ALONG ITS LENGTH. 



V IV 



I V IV 



I XII XI X IX VIII VII VI V IV III II I VIII VII VI V IV 



FIG. 106. DIAGRAM SHEWING THE VARIATIONS IN THE SECTIONAL AREA OF THE 

 ANTERIOR COLUMNS OF THE SPINAL CORD, ALONG ITS LENGTH. 



IS 

 10 



5 

 



V IV III || 1 V IV III II 1 XII XI X IX VIII VII VI V IV III II 1 VIII VII VI V IV 111 II 



FIG. 107. DIAGRAM SHEWING THE VARIATIONS IN THE SECTIONAL AREA OF THE 

 POSTERIOR COLUMNS OF THE SPINAL CORD, ALONG ITS LENGTH. 



lateral columns respectively we find that while the sectional area 

 of the lateral column (Fig. 105) increases with some considerable 

 regularity from below upwards, though not so regularly as does 

 the whole area of white matter, both the anterior (Fig. 106; and 

 the posterior (Fig. 107) columns agree to a certain extent with 

 the grey matter in shewing a decided increase in both the lumbar 

 and the cervical swellings. We may, provisionally at least, infer 

 from this that, while considerable portions of both the anterior and 

 the posterior columns are like the adjoining grey matter in some 

 way or other concerned in the exit and entrance of efferent and 

 afferent fibres, the larger portion of the lateral column is concerned 

 in the transmission of impulses to and fro, between the local 

 mechanisms below, immediately connected with the several spinal 

 nerves, and the brain above. This conclusion seems incidentally 



