350 



HITCHCOCK'S ANATOMY 



seems clearly established, that one portion of each nerve trans- 

 mits the sensation to the brain, called the centripetal or sen- 

 sory, and the other conveys the order to the muscle, called the 

 centrifugal or motor, yet no anatomical difference can be de- 

 tected between the different fibers of the nerve. From this 

 fact a German physiologist has made a series of curious cal- 

 culations, as a result of which he concludes that nervous in- 

 fluence, such as the will to move a certain muscle, travels at 

 the rate of 195 feet per second. 



629. Ganglia Reservoirs of Power —It has been sug- 

 gested, and with reason, that the ganglia, abundant as they are 

 in the body, act as reservoirs of nerve force, and the frequent 

 commissures, or union and subsequent divergence of nerve 

 fibers, is to draw off a part of the influence which is coming 

 along the centripetal fiber, and directing it into a new chan- 

 nel. 



630. Divisions of the Cranial Nerves— The cranial 

 nerves may be divided, according to their function, into three 

 groups : 



Olfactory. 



Special Sense •{ Optic. 



Auditory. 



Motores Oculorum. 

 Patbeticus. 

 Abducentes. 

 Facial. 

 Lingual. 

 Trifacial. 



Glosso-Ph aryngeal. 

 Par Yagum. 

 I Spinal Accessory. 



631. The olfactory nerve is the one by which we g&in the 

 smell of odoriferous substances, as they are brought in con- 

 tact with this nerve in the lining membrane of the nose. 



What are the centripetal and what the centrifugal fibers of the nerves ? What is a 

 probable rate at which the influence is transmitted through the nerves to and from the 

 brain ? 629. What theory has been offered for the use of the ganglia? 630. What three 

 groups of the cervical nerves are here given ? 631-640. State the function of each pai* 

 of the cranial nerves. 



Motion. 



Compound , 



