FEOQ 253 



ferences in size, color, direction, branches, etc. Make a 

 diagram of the spinal nerves as seen from the ventral side. 



5. The Sympathetic System. 



This is best seen in a specimen from which the 

 internal organs have been removed from one half 

 of the body. Push the remaining organs to one 

 side to see the nerves which supply them. The 

 principal part of the sympathetic system consists 

 of a row of nerves and ganglia lying on each side 

 of the ventral median line of the spinal column. 

 From the ganglia and nerves arise branches which 

 run to the lungs, heart, principal blood-vessels, 

 stomach, intestine, hver, kidneys, genital glands, 

 etc. ; to the spinal and cranial nerves ; and be- 

 tween the various parts of the sympathetic sys- 

 tem. 



How do the sympathetic compare in size with 

 the spinal nerves? How many sympathetic gan- 

 glia do you find? What noticeable differences 

 between these and the spinal ganglia can you 

 detect ? 

 Make a diagram of the sympathetic nervous system. 



c. The cranial nerves. 



To see these well, two specimens should be 

 prepared, one to show a ventral view of the in- 

 side of the skull, the other to show the ventral 

 surface of the brain. The second may be pre- 

 pared by removing one half of the floor of the 

 mouth, the mucous membrane of the roof of the 

 mouth, and the floor of the cranium and of the 

 auditory capsules. Especial care must be exer- 

 cised in order not to tear away the nerves from 

 the parts to which they are connected. 



