WORK UPON VISCERAL AXD ALLIED NERVES. 53 



According to Steinach, the upper part of the small 

 intestine of the frog receives motor fibres through the 

 posterior roots of the fourth and fifth nerves, the lower part 

 through the fifth and sixth. 



Vaso-fuotor N'erves to the Intestines. — The course of the 

 vaso-constrictors to the stomach and small intestine has 

 long been known to be by the splanchnics. Langley and 

 Dickinson ^ showed that their course was interrupted by 

 nerve cells which were placed in the coeliac or superior 

 mesenteric ganglia. Painting the ganglia with nicotine 

 abolishes the usual effect on the blood pressure, of stimula- 

 tion of the splanchnic. The local application of nicotine to 

 the ganglia causes first a rise in blood pressure, stimu- 

 lating action on the nerve cells, followed by a marked fall 

 as the cells become paralysed. In a recent paper, Langley^ 

 gives further evidence of the position of the cells on the 

 course of the vascular fibres to the intestine. After a suffi- 

 cient dose of nicotine, the marked rise in blood-pressure 

 consequent on stimulation of the splanchnic is abolished, 

 but stimulation of the nerves leaving the solar plexus can still 

 produce the usual rise in blood-pressure. He concludes 

 that there is one, and only one, cell station on any vaso- 

 constrictor nerve. Contejean, ^ for the frog, describes 

 both vaso-dilators and constrictors as occurring in the 

 vagus, the dilators being present to the greatest extent. 

 The main number of the constrictors reach the organ by the 

 sympathetic chain. ^ Hallion and Fran9ois Franck^ have 

 recently published some experiments upon the origin and 

 course of these nerves. Their method is a plethysmo- 

 graphic one and consists in enclosing one or more loops of 

 the intestine in a glass vessel in which it is covered by 

 warm saline solution. The upper orifice is closed by an 

 air-tight lid, and changes in pressure of the air imprisoned 

 over the salt solution are recorded by means of a sensitive 



^ Proc. Roy. Soc, vol. xlvi., p. 423, 1889. 

 "^/ourn. of Physiol., vol. xx., p. 223, 1896. 

 ^ Camp, rend., vol. cxiii., p. 150, 1891. 

 ^ Arc/i. de P/iysiot., vol. xxiv., p. 640, 1892. 

 ^ Ibid., vol. xxviii., pp. 478 and 493, 1896. 



