4:28 NERVOUS SYSTEM. 



ence of a certain degree of sensibility in the ganglia of the 

 sympathetic system. 



As regards excitability, recent experiments are quite 

 satisfactory. Miiller exposed the intestines and the semi- 

 lunar ganglia in rabbits ; and, having waited until the intes- 

 tines, which generally present movements on first opening 

 the abdomen, had ceased their contractions, the peristaltic 

 movements " were immediately renewed with extraordinary 

 activity " by touching the ganglia with caustic potash. 1 The 

 experiments of Longet show that a feeble continued galvanic 

 current applied to the great splanchnic nerves produces con- 

 tractions of the muscular coat of the intestines, when they 

 contain alimentary matters, but that no contractions occur 

 when they are empty. a On the other hand, Pniiger has ob- 

 served that galvanization of the splanchnic nerves produces 

 a passive condition of the small intestine ; that is, arrest of 

 its movements without persistent contractions of its muscu- 

 lar coat ; but these results were not confirmed in analogous 

 experiments performed by Biffi. 8 More recently, in a series 

 of very elaborate experiments, by Legros and Onimus, it has 

 been shown that the induced galvanic current applied to the 

 splanchnic nerves does not produce peristaltic movements, but 

 that these movements are excited by the constant current. 4 



Taking into consideration the most reliable direct obser- 

 vations upon the sympathetic ganglia and nerves, the fact 

 that their stimulation induces movements in the non-striated 

 muscles to which they are distributed can hardly be doubted. 

 This action is particularly well marked in the muscular coat 

 of the blood-vessels ; but here, the function of the nerves is 

 so important, that it merits special consideration, and will 



1 MiJLLER, Elements of Physiology, London, 1840, vol. i., p. 713. 



2 LONGET, Traite de phyisologie, Paris, 1869, tome iii., p. 595 ; and, Anatomie 

 ct physiologic du systeme nerveux, Paris, 1842, tome ii., p. 568. 



3 PFLUGER ET BIFFI, Sur une systeme qui suspend les mouvemcnts de Pintestin 

 grele. Journal de la physiologic, Paris, 1858, tome i., p. 421. 



4 LEGROS ET ONIMUS, Recherches experimentales sur les mouvements de Vintestin. 

 Journal de I'anatomie, Paris, 1869, tome vi., p. 196. 



