540 



THE SPINAL CORD AND ITS MEMBRANES. 



small terminal fibrous cord before referred to ; but the membrane 

 is to be raised while it is being cut through, so that the loose arach- 

 noid on the cord may not be injured. After its division, fasten 

 back the dura mater to a long cork strip with pins. 

 Deep surface The inner surface of the dura mater is now seen to be smooth 



of dura 

 mater. 



Ic 



FIG. 194. LOWER END OF 

 THE DURA MATER WITH 

 ITS CENTRAL AND LATERAL 

 PROCESSES. 



a. Sheath of dura mater. 



b. Central fibrous band fix- 

 ing it to the coccyx. The 

 lateral offsets encasing the 

 last two lumbar, the five 

 sacral, and the coccygeal 

 nerves are also shown. Each 

 nerve is marked by the 

 numeral, and the first letter 

 of its name. 



FIG. 195. MEMBRANES OF THE SPINAL 

 CORD. 



a. Dura mater cut open and reflected. 



b. Small part of the translucent arachnoid. 

 h. Pia mater, closely investing the spinal 



cord. 



c. Ligamentum denticulatum on the side 

 of the cord, shown by cutting through the 

 anterior roots of the nerves. 



d. Processes joining it to the dura mater. 

 c. Anterior roots of the nerves, cut ; and 



/, posterior roots, each entering a separate 

 hole in the dura mater. 

 g. Linea splendens. 



Subdural 

 space. 



Arachnoid 

 membrane 

 is loose, 



and shining, and everywhere free except at the spots along each side 

 where it is perforated by the nerves, and where it gives attachment 

 to the processes of the liganientimi denticulatum. The cavity 

 between the dura mater and the arachnoid is named the subdural space. 

 The ARACHNOID (fig. 195,6) is the thin translucent covering of 

 the cord immediately beneath the dura mater. It surrounds the 



