THE SYMPATHETIC SYSTEM 259 



nerve does not exist and what is taken for a nerve is a 

 series of communications between nerve centres. 



"These nerve centres are the ganglia. Scattered over 

 various regions of the body, they have an isolated and 

 independent action. Each is a focus sending out a 

 number of branches carrying to certain organs the 

 impulses from the focus from which they arise. Among 

 these branches, some go from one ganglion to the other and 

 as these branches together look like a continuous structure, 

 this structure has been considered as one nerve. These 

 branches are simply anastomosis and not a nerve in itself. 



"From now on, I will divide my descriptions of the nerves 

 into two great systems. One arising from the brain, the 

 other from the ganglia. The first has a single centre, 

 the other a multitude. I will first examine the divisions 

 of the central nervous system; afterwards I will take up the 

 system of the ganglia which can be divided into those of 

 the neck, head, thorax, abdomen and pelvis. 



"In the head we find the lenticular ganglion, Meckel's 

 ganglion, that of the sublingual gland, etc. In spite of the 

 fact that no communication exists between these centres, 

 either among themselves or to the so-called greater 

 sympathetic, their description belongs to the latter since 

 these communications are only accessories to this system 

 of nerves. In the neck, the three cervical ganglia and 

 sometimes one other, on the side of the tracheal artery; 

 in the chest the twelve thoracic; in the abdomen the 

 semi lunar and lumbar ganglia, etc. ; in the pelvis the sacral 

 ganglia, these are the different centres to w r hich are 

 attached a number of branches which have to be examined 

 separately as we examine the cerebro spinal system. In 

 the same manner in the neck and the head, each ganglion 

 will be described, then its branches will be taken up. As 

 the ganglia of the chest, the lumbar region and pelvis have 



