STRUCTURE OF THE VERTEBRATES 



283 



to either side of the midline, is a metameric group of autonomic 

 vertebral ganglia. These are connected in series with each other, 

 and through the rami communicantes with the spinal nerves. 

 Each ramus communicans is composed of the visceral motor and 



Muscle 



Hair 



Sweat gland 



Capillary 



Tig. 161. Diagrammatic Cross Section of the Body. The pathways of the 

 somatic and visceral nerves are shown. The dotted lines indicate the auto- 

 nomic motor fibers from the vertebral ganglia to the integumentary region 



of the body. 



the visceral sensory fibers of the spinal nerve. In addition, un- 

 myelinated motor fibers pass from the ganglia to the somatic 

 regions of the body, forming the gray ramus. These fibers pass 

 to the skin with the somatic fibers of the cord and innervate the 



