334 MECHANISMS OF THE DIGESTIVE TRACT. 



different course from the vasomotor fibres, and that section of the 

 nerves running from the suprarenals to the solar plexus annuls the 

 inhibitory action of the splanchnics without affecting their vaso- 

 constrictor effect. 



Besides these inhibitory effects, various observers have recorded a 

 motor effect on stimulating the splanchnics (Schiff, Ludwig and Kupffer, 

 Bechterew and Mislawsky, Bunch). The last-named observer has given 

 graphic records of intestinal movements, in which stimulation of the 

 splanchnics caused in some animals augmentation, in others inhibition, 

 of intestinal tone, and in some cases primary augmentation followed 

 by inhibition ; and concludes that nerve fibres of opposed function run 

 in the splanchnics, and that the result obtained is due to the prepon- 

 derating influence of one or other kind in the particular animal 

 employed. I have myself never obtained any other effect than inhibi- 

 tion on excitation of these nerves. 



In 1885, Ehrmann 1 put forward the view, that the intestines conformed to 

 v. Basch's idea of " crossed innervation," and that the splanchnics were motor 

 for the longitudinal but inhibitory for the circular coat. Courtade and Guyon, 2 

 on the other hand, found that the splanchnics produced contraction of the 

 circular and inhibition of the longitudinal coat. Their method of recording 

 the movements of the two coats does not appear to offer any criterion for 

 distinguishing active from passive movements of the intestinal wall. These 

 authors find that when the intestines are in an abnormal condition, Ehrmann's 

 results may be obtained, and conclude, therefore, that the splanchnics 

 contain motor and inhibitory fibres for both layers of muscle. 



Observations by Bayliss and myself 3 lend no support to the theory 

 of crossed innervation in either of its versions'. Eecordirig the con- 

 tractions of each coat by means of two enterographs, placed at right 

 angles to one another, we have found that both coats contract 

 synchronously, and that the contractions of both are inhibited on 

 stimulating the peripheral end of either splanchnic nerve. So far as 

 concerns the vagus, although the initial inhibitory effect is produced 

 equally on both coats, the subsequent augmentation is confined 

 almost entirely to the circular coat. 



Bechterew and Mislawsky 4 and Bunch have investigated the spinal 

 nerve-roots which contribute fibres through the sympathetic to the 

 intestines. According to Bunch, the nerve fibres pass to the splanchnic 

 from the anterior roots, from the sixth thoracic to the second, third, 

 fourth, or fifth, lumbar nerves, and have one cell station on their 

 course (in the ganglia of the solar plexus). 



Central and reflex influences. According to Bechterew and 

 Mislawsky, stimulation of the sigmoid convolution in dogs, or of the 

 posterior corpora quadrigemina, influences the intestinal contractions ; 

 these being inhibited or augmented according to the exact localisation 

 of the stimulus. Hence they locate "centres for intestinal move- 

 ments " in these parts of the brain. Somewhat similar results were 

 obtained by Bochefontaine, 5 and by Pal and Bergriin. 6 



It is probable that the intestinal movements, like those of the 

 stomach, may be inhibited or reinforced under the influence of 



1 Med. Jahrb., Wien, 1885. 2 Arch, de physiol. norm, etpath., Paris, 1897, tome ix. 



3 Journ. Physiol., Cambridge and London, 1899, vol. xxiv. 



4 Arch.f. Physiol., Leipzig, 1889, Suppl. S. 254. 



5 Arch, de physiol. norm, et path., Paris, 1876, tome iii., p. 164. 



6 Med. Jahrb., Wien, 1888, Bd. viii. (quoted by Mislawsky). 



