TISSUES. 



99 



Nerve Fibers. i. Medullated Fibers. Medullated 

 nerve fibers usually consist of three parts, (a) axis 

 cylinder, (6) medullary sheath, (c) neurilemma. An 

 axis cylinder is a cell process that carries an impulse 

 away from the nerve cell. It is a slender cytoplasmic 

 process and may be very long, as is the case with 



Fig. 66. Ganglion cell from the Gasserian ganglion of a rabbit; stained 

 in methylene-blue (intra vitani) (Huber). 



the motor fibers that come from nerve cells in the 

 anterior horn of the spinal cord and extend, without 

 interruption, to muscles in the distal parts of the 

 limbs. The axis cylinder presents a longitudinal 

 striation, a fibrillar structure, that is supposed to be 

 continuous with the cytoplasmic striation of the 



