146 



THE HUMAN JiODY. 



If we should cut into the elbow to find the " funny- 

 bone," we would come upon a flat, shining cord about an 

 eighth of an inch wide. If we should follow this cord 

 down, we would find it divide into smaller cords; and, if 

 we should follow each one of these, we would see it finally 

 ending in the muscles, or in the skin, or some other tissue, 

 in a great many fibers, so fine that only a microscope 

 would show them. Many of them go to the little finger, 

 where the tingling is most felt. If we should search 

 farther for such cords, we would find that they were in 

 nearly every part. We would find that some of them 

 were as large as the one first seen, but that the smallest 

 were smaller than the capillary blood-vessels, and as 

 numerous. 



11, If, starting from the elbow, we should follow the 

 cord first found up the arm, we would see it joining other 

 cords, and perhaps itself dividing ; and finally we would 

 trace it through one or more of the openings between the 



vertebra? (intervertebral fora- 

 mina) into the spinal cord. 



If we followed any other 

 cord up, it would lead us 

 finally into the spinal cord 

 or the brain. Most of these 

 white cords, which are the 

 nerves, have one end divided 

 into the finest of fibers in 

 the different parts of the 

 body, and the other end in 

 the spinal cord or brain. 

 The brain and spinal cord are called the nerve centers. 



12. By examination with the microscope, it is found 



Fig. 56. 

 NERVE-CELLS (Magnified). 



