, 



THE NEOPALLIUM. 



645 



misphere which lies subjacent to the gray cortex is composed of medulla ted nerve- 

 fibres, arranged in a very intricate manner. But the arrangement of these fibres 

 cannot be properly understood until the configuration of the surface of the hemi- 

 sphere has been considered. 



FIG. 574. DIAGRAM TO ILLUSTRATE THE MINUTE STRUCTURE OP THE CEREBRAL CORTEX AND 



EXPLAIN HOW IT INFLUENCES THE MACROSCOPIC APPEARANCE. 



VNeuroglia cells. 



A 

 B 



C. Cell with short axon (N) which breaks 



up in a free arborisation. 



D. Spindle-shaped cell in stratum zonale. 



E. Small pyramidal cell. 



F. Large pyramidal cell. 



G. Cell of Martinotti. 

 H. Polymorphic cell. 

 K. Cprticipetal fibres. 



THE JSTEOPALLIUM. 



Fibre-tracts proceed into different districts of the neopallium from the various 

 nuclei of the thalamus to serve as the channels through which tactile, visual, 

 acoustic, and other kinds of sensory impressions are poured into it. These districts 

 may be regarded as the receptive sensory areas, tactile, visual, acoustic, etc. ; but 

 around each sensory area there is differentiated a series of more or less concentric 

 bands of neopallium, which are related to an incoming sensory path only through the 

 intermediation of the sensory area which it fringes. Finally, there are interposed 

 between the sensory area and its fringing bands of one sense and those of 

 another, certain association areas, which cannot be regarded as the territory of 



425 



