660 



STRUCTURE OF THE CEREBRUM 



[CH. XLVI. 



We are now in a position to complete diagram 448 (p. 613), and 

 obtain an idea of the relations of the principal cells and fibres of the 

 cerebro-spinal nervous system to one another. 



Pyr. (fig. 482) is a cell of the Rolandic area of the cerebral cortex ; AX is its 

 axis-cylinder process which passes down in the pyramidal tract, and crosses the 



A.C.N 



Multipolai 



Cell of Ant 



Horn 



FIG. 482. Scheme of relationship of cells and fibres of brain and cord. (In the preparation of this 

 diagram I have received considerable assistance from Dr Mott.) 



middle line AB at the pyramidal decussation. It gives off collaterals, one of which 

 (call) is shown passing in the corpus callosum to terminate in an arborisation in the 

 cortex of the opposite hemisphere ; another (str} passes into the corpus striatum. 

 In the cord collaterals pass off and end in arborisations round cells of the anterior 

 horn of the spinal cord (see also fig. 448) ; the main fibre has a similar termination. * 



* The intermediate cell station in the posterior horn between the pyramidal fibre 

 and the anterior cornual cell (Schafer) is not shown in the diagram (see also p. 613). 



