THE CEREBELLAR CORTEX. 



413 



In the gray commissure, nearer its anterior border, is situated 

 the central canal of the spinal cord, continuous above with the 

 ventricular cavity of the medulla and terminating caudally in the 

 filum terminale. This canal is not patent in the majority of adults, 

 being occluded from place to place. The canal is lined by a layer 

 of columnar cells, developed from columnar cells, known as spongio- 

 blasts, lining the relatively larger canal of the embryonic spinal 

 cord. In young individuals these cells are ciliated and their basal 

 portions terminate in long, slender processes in which are embedded 

 neuroglia fibers. 



B. THE CEREBELLAR CORTEX, 



In the cerebellar cortex we distinguish three general layers 

 the outer molecular, the middle granular (rust-colored layer), and 

 the inner medullary tract. 



Blood-vessel.- V- ~ 



** . " --' * - 41 ^> i 



... Nerve-fiber layer. 



- - * ... -j^_ _-^ 



Fig. $30. Section through the human cerebellar cortex vertical to the surface of the con- 

 volution. Treatment with M tiller's fluid ; X XI 5- 



The molecular layer contains three varieties of nerve-cells, 

 those of Purkinje, which border upon the granular layer, the stel- 



