DRAINAGE AREAS OF THE SKULL 143 



lying it, viz. the similarity existing between the anterior 

 and posterior, or upper and lower central lymph exit 

 arrangements of the central systemic nervous system, i.e. 

 between the infundibulum, pituitary gland, and attached 



FIG. 59. SECTIONS SHOWING THE GENERAL RELATIONS OF THE SPINAL 



CORD TO THE INCLOSING THECA, AND OF THIS TO THE VERTEBRAL 

 CANAL. (Key and Retzius.) 



A, through the fifth cervical vertebra ; B, through the tenth dorsal vertebra ; C, 

 through the first lumbar vertebra and the foramen of exit of the twelfth dorsal 

 nerve-roots ; D, through the disk between the second and third lumbar vertebrae; 

 E, through the first sacral vertebra. In A, B, and C, the cord, covered by pia 

 mater, is seen in the centre, with the ligamentum denticulatum attached to it on 

 either side ; the nerve-roots on either side form small groups which, since they 

 pass obliquely downwards to their foramina of exit, are cut across ; the dura 

 matral sheath is separated by a considerable space from the cord, and by a 

 quantity of loose areolar and fatty tissue from the wall of the vertebral canal. 

 This tissue is in smaller amount in C. D and E are below the termination of the 

 cord, and show sections of the nerve-bundles of the cauda equina within the theca, 

 which is very large in D, but comparatively small in E, the vertebral canal in the 

 latter being largely occupied by adipose tissue In this are seen the sections ot 

 two large veins. The arachnoid is not represented in any of these sections. 



excretory mechanisms, anteriorly or centrally, and the 

 filum terminate , the coccygeal gland, and related excretory 

 mechanisms posteriorly the infundibulum having^ in fact, 

 been even called the anterior filum terminate by some of 

 these observers. 



