THE TWO ROOTS. 217 



it may still be callod the sensitive nerve of the face; 

 that the trigeminus is the only nerve of the brain that 

 bestows sensibility to the face, except a few branches 

 from the cervicals, which may be traced to the lower 

 part of it ; that there are some anatomical facts which 

 incontestably prove that the motor nerve exists : that 

 Sir Charles Bell laid the root of the trigeminus bare in 

 an as3 immediately after the animal's death, and that 

 on irritating the nerve the muscles of the jaw acted 

 and the jaw closed; that he divided the root of the 

 nerve in a living animal, and the jaw fell ; * that he 



*" Re-establishment of Sensibflity after Resection 

 OF Nerves. — A memoir by MM. Aiioing and Tripier was read 

 before the Frencli Academy, November 28th, on the effect of re- 

 section of certain nervous trunks. Clinical facts have several 

 times shown that after wounds which have altered or destroyed 

 a portion of a nerve, sensibility rstiirns in the integuments to 

 which the nerve is distributed. MM. Arloing and Tripier made 

 nervous resections in dogs, and saw sensibility reappear after a 

 certain time in the integuments to which the branches of the 

 nerve were distributed, and in the peripheral end of the nerve 

 itsolf." — Popular Science Reviem, 1SG7. 



" How Motor-Nerves End in Non-strtated Muscular 

 Tissue. — A very A^aluable communication stating the results of 

 M. Henocque's researches has been published in " TArchives de 

 Physiologie," and may be thus abstracted: 1. The distribution 

 of the nerves in smooth muscle is not only identical in man and 

 other vertebrate animals in which it has been observed, but is 

 essentially similar to all the organs containing smooth muscle. 



2. B?fore tenninating in the smooth muscle, the nerves form 

 three distinct plexuses or networks — [n) a chief or fundamental 

 plexus, containing numerous ganglia, and situated outside the 

 smooth muscle ; {h) an intermediate plexus ; and (c) an intra- 

 muscular plexus, situated idthin the fasciculi of smooth fibers. 



3. The terminal fibrils are everywhere identical. They divide 

 and suhdi\'ido dichotomously, or anastomose, and terminate by 

 a slight swelling or knob, or in a punctiform manner. The ter- 



10 



