540 THE NERVOUS SYSTEM 



Under central or transmitting neurones are included those units which 

 act as connecting links within the central organ, especially within coordi- 

 nate parts of the central nervous system, between the afferent and efferent 

 neurones. 



Nerve Centers. Whenever a number of neurones are gathered in 



FIG. 359. View of the Cerebro-spinal Axis of the Nervous System. The right half of 

 the cranium and trunk of the body has been removed by a vertical section; the mem- 

 branes of the brain and spinal cord have also been removed, and the roots and first part of 

 the fifth and ninth cranial, and of all spinal nerves of the right side, have been dissected 

 out and laid separately on the wall of the skull and on the several vertebrae opposite to the 

 place of their natural exit from the cranio-spinal cavity. (After Bourgery.) 



