Chap, i.] 



THE SPINAL CORD. 



685 



or below the level of the entrance, on the same side or on the 

 opposite side. In other words, an afferent impulse passing 

 along the posterior root may, according to the course which it 



- — m.t. 



i 



pr - / 



At. 



Fig. 112. Transverse Dorso ventral Section of the Spinal Cord (Human) 

 at the Level of the Third Lumbar Nerve. (Sherrington.) 



This is drawn to the same scale as Fig. 110, and in the same way except 

 that the outline of the grey matter is not exaggerated. Pr'. median, Pr. inter- 

 mediate, Pr". lateral bundles of posterior roots. The region comprised under 

 m.t. is the marginal zone or Lissauer's zone. The other letters of reference are 

 the same as in 110 and 111. 



The three figures 110, 111, 112 are intended to illustrate the main differential 

 features of the thoracic, cervical, and lumbar cord. 



