236 



STUDENTS HISTOLOGY 



deeper parts of the brain -substance, the study of which does not 

 come within the limits of this work. 



The brain -substance does not differ essentially from the cord, 

 except in the arrangement of its parts. The nerve -fibers are 



I iM-i 



,j ntL ii , n ) 



FIG. 153. LAYERS OF THE HUMAN CEREBRAL, CORTEX. (MEYNERT.) 

 The numbers refer to the layers given in the text, page 238. 



mostly medullated, but have no neurilemma. The gray substance 

 is arranged in five layers, which are in some instances quite 

 sharply defined, and oftener demonstrable only with considerable 

 difficulty. Transversely running bands of medullated nerve -fibers 



