CRANIAL NERVES. 445 



section of these has been made, there are first symptoms of 

 impending suffocation from the paralysis of the larynx, but 

 these soon pass off, as the desire to respire is in a great 

 measure abolished. The respirations take place slowly and 

 at long intervals, often only three or four per minute, and 

 death takes place in a space of time varying from twenty- 

 four hours to six days. The lungs are throughout in a state 

 of splenization, having a dark purple colour, and a leathery, 

 resistent feeling, being incapable of crepitating, and infil- 

 trated with blood. They sink in water. This seems de- 

 pendent on the stasis of blood within their substance, and 

 the collapse of the air-cells from deficient inspiration. In- 

 flammatory spots, which sometimes appear, are referable to 

 the irritation caused by foreign bodies which have passed 

 unchecked through the paralysed larynx. 



The action of this nerve on the heart is not well under- 

 stood. After its section the heart's action is usually acce- 

 lerated ; but this probably depends entirely on the excited 

 condition of the animal. 



The pneumogastric presides over the movements of the 

 stomach : when it is divided the organ is to a great extent 

 paralysed ; and, on the other hand, galvanising its trunk 

 causes rhythmical movements of the stomach. Its section 

 does not interfere with the sensation of hunger. The action 

 of this nerve on the gastric secretion is disputed. Bernard 

 found that its section led to an immediate stoppage of 

 secretion, the previously turgid mucous membrane be- 

 coming pale and bloodless ; and this condition persisted for 

 days, and any food in the organ underwent decomposition. 

 Others contest this opinion, and believe the cessation of 

 secretion to depend on the shock to the system and the 

 absence of muscular movement, which stimulated the 

 mucous membrane, by bringing it in continual contact 



