THE SPINAL CORD 83 



CHARACTERISTIC FEATURES OF TRANSVERSE SECTIONS AT VARIOUS LEVELS OF THE SPINAL CORD 



umn on the one side, and the posterior median septum on the other. The sep- 

 tum, just mentioned, completely separates the two posterior funiculi from each 

 other. Incomplete septa project into the white substance from the enveloping 

 pia mater. One of these, more regular than the others, enters along the line of 

 the posterior intermediate sulcus. It is restricted to the cervical and upper 

 thoracic segments, is known as the posterior intermediate septum, and divides 

 the posterior funiculus into two bundles, the more medial of which is known 

 as the fasciculus gracilis, while the other is called the fasciculus cuneatus. 



Characteristics of the Several Regions of the Spinal Cord. It will be ap- 

 parent from Figs. 55-58 that the size and shape of the spinal cord, as seen in 

 transverse section, varies greatly at the different levels and that the relative 

 proportion of gray and white matter is equally variable. Two factors are 



