THE NERVOUS SYSTEM. 



89 



posed of bundles of connective tissue which cross at various angles, and 

 in whose interstices branched connective-tissue corpuscles lie: it is lined 

 by a thin elastic membrane, and on the inner surface, and, where it is not 





FIG. 315. View of the cerebro- spinal axis of the nervous system. The right half of the cranium 

 and trunk of the body has been removed by a vertical section; the membranes of the brain and 

 spinal marrow have also been removed, and the roots and first part of the fifth and ninth cranial, and 

 of all the spinal nerves of the right side, have been dissected out and laid separately on the wall of 

 the skull and on the several vertebrae opposite to the place of their natural exit from the cranio- 

 spinal cavity. (After Bourgery.) 



adherent to the bone, on the outer surface also, is a layer of endothelial 

 cells very similar to those found in serous membranes. (2.) The Arach- 



