HUMAN SPINAL COED. 



189 



cent, unstained white substance of Schwann. (These are medul- 

 lated fibres.) (d) The few and scattering axis cylinders without 

 surrounding white substance. (Non-medullated nerves.) (e) The 

 neurilemma, appearing as a thin, violet ring around the white sub- 

 stance of Schwann. (Most medullated nerves of the cerebro-spinal 

 .system are provided with this sheath.) (/) The small, about one- 

 three thousandth of an inch, deeply haema. -stained cells of the 

 neuroglia. (g) The neuroglia substance, finely granular or 

 fibrillated, between the nerve fibres, (h) The spider cells (Deiter's) 

 of the neuroglia. (These are not numerous, but easily found near the 

 periphery.) (i) The longitudinal nerve fibres passing from the an- 



FIG. 123. SAME SPECIMEN AS SHOWN IN FIG. 122. MORE HIGHLY MAGNIFIED. REGION OF AN- 

 TERIOR CORNU. x 350. 



A. Medullated filaments passing out from the gray substance to form the anterior root of 

 a spinal nerve. 



B. Ganglion cells. 



C. Neuroglia nuclei. 



D. Blood-vessels. 



E. One of the transversely divided medullated fibres of the white substance, anteriorly to 

 the anterior gray cornu. The line leads to the neurilemma. 



F. White substance of Schwann of last. 



G. The axis cylinder of E. 



terior gray cornu to form the anterior root of a spinal nerve, (j) The 

 different size of the nerve fibres in different areas of the section. 

 (Note the small fibres of the postero-internal column.) (k) The 

 blood-vessels. (These vessels are largely confined to the neuroglia- 

 septa, which pass in from the pia. These septa contribute to the 



