226 THE NERVOUS SYSTEM 



from its under surface fine fibrillae which are said to pass between 

 the muscular fibrillae which make up the fiber. Sensory fibers 

 are somewhat scantily distributed to the voluntary muscles. 



In plain muscle tissue the motor nerves are distributed after 

 the same general manner as in the striped muscles, though with 

 some differences. Here the fibers are not medullated, and 



Nerve-fibre. 



End-plate. 



Muscle nucleus. 



FIG. 69. Termination of a nerve fiber in end-plate of a lizard's muscle. 



(Stirling.) 



primitive fibrils passing from the intermediary plexus finally 

 enter the nuclei of the muscle cells. 



Medullated fibers have been traced to the cells of glands, 

 but not farther. It is thought by some that, having formed a 

 plexus, non- medullated fibeis pass in to terminate in the nu- 

 cleoli of the gland cells, though such endings have not been 

 demonstrated. 



The peripheral distribution of nerves connected with the 

 special senses will be discussed elsewhere. 



The remaining methods of termination above noted apply to 

 afferent nerves. It is claimed that a very large number of sen- 

 sory nerves terminate in hair-follicles. If such be the case it 

 will account for sensory terminations in by far the greater part 

 of the cutaneous surface. It is supposed that nerve fibrillae form 



