SPINAL CORD. 



capped by the substantia gelaiinosa. The gray matter consists primarily of a 

 framework of fine connective tissue, supporting blood-vessels, lymphatics, 

 medullated and non-medullated nerve-fibers, and groups of nerve-cells. 



I 



FIG. 21. SUPERIOR, MIDDLE, AND INFERIOR PORTIONS OF SPINAL CORD. 

 i. Floor of fourth verticle. 2. Superior cerebellar peduncle. 3. Middle cerebellar 

 peduncle. 4. Inferior cerebellar peduncle. 5. Enlargement at upper extremity of 

 postero-median column. 6. Glosso-pharyngeal nerve. 7. Vagus. 8. Spinal acces- 

 sory. 9, 9, 9, 9. Ligamentum denticulatum. 10, 10, 10, 10. Posterior roots of spinal 

 nerves, n, n, n, n. Postero-lateral fissure. 12, 12, 12, 12. Ganglia of posterior 

 roots. 13, 13. Anterior roots. 14. Division of united roots into anterior and pos- 

 terior nerves. 15. Terminal extremity of cord. 16, 16. Filum terminale. 17, 17. 

 Cauda equina. I, VIII. Cervical nerves. I, XII. Dorsal nerves. I, V. Lumbar 

 nerves. I, V. Sacral nerves. (Sappey.) 



The nerve-cells are arranged in groups, which extend for some distance 

 throughout the cord, forming columns more or less continuous. The first 

 group is situated in the ventral horn, the cells of which are large, multipolar, 

 and connected with the ventral roots of the spinal nerves, and are supposed 

 to be motor in function. The second group is situated in the dorsal horn, 



