PULMONARY SERVES. 239 



nerves to respiration. We have already mentioned the ar- 

 rest of the respiratory movements by galvanization of the 

 superior laryngeal branches and of the central ends of the 

 nerves after their division in the neck. 1 The main point 

 of interest in this connection is the fact that the effects 

 observed are entirely reflex, galvanization of the peripheral 

 ends of the divided nerves having no direct action on the 

 movements of the thorax. 



In view of the very indefinite physiological applications 

 of the experiments made by galvanizing the nerves, we will 

 not give in detail the numerous observations upon this sub- 

 ject, but simply state the results, as given in a recent and 

 very elaborate work on respiration, by M. Bert : 2 



" 1. Respiration may be arrested by excitation of the 

 pneumogastrics (Traube), of the larynx (Cl. Bernard), of 

 the nostrils (M. Schiff ), of most of the sensory nerves (M. 

 Schiff, an assertion that I have not been able to verify). 



" 2. This arrest may take place eith,er in inspiration or in 

 expiration, through any one of these nerves, without attrib- 

 uting it to the action of derived currents. 



" 3. A feeble excitation accelerates the respiration ; a 

 more powerful excitation retards it ; a very powerful excita- 

 tion arrests it. These words feeble ' and i powerful ' hav- 

 ing, it is understood, only a relative sense for any one animal 

 and under certain conditions : what is feeble for one would 

 be powerful for another, etc. 



"I believe, in opposition to the opinion of Eosenthal, 

 that section of the pneumogastrics does not increase the 

 difficulty of arresting respiration ; at least, death by ex- 

 citation occurs much more easily in this case. 



". When the respiratory movements are completely 

 arrested, it is always the same for the general movements 

 of the animal, which remains motionless. 



1 See page 219. 



9 BERT, Lemons sur la physiologie comparee de la respiration, Paris, 1870, p. 

 489, et seq. 



116 



