52 



SCIENCE PROGRESS. 



saline solution, and confirmed the ordinary effects of vagus 

 and splanchnic, finding, however, that the vagi usually had 

 unequal actions, sometimes the left sometimes the right 

 producing greater peristalsis. Bechterew and Mislawski^ 

 experimented with the object of determining the roots by 

 which the fibres in the splanchnic innervating the small 

 intestine left the cord. They found them in the anterior 

 roots of the sixth thoracic to first lumbar inclusive. 



Langley and Dickinson' showed that painting the 

 superior mesenteric ganglion with nicotine abolished the 

 effect of splanchnic stimulation, and that the motor fibres 

 of the vagus do not end in cells of the solar plexus. Further, 

 Gaskell ^ showed by the method of degeneration that in 

 all probability the motor fibres of the vagus are connected 

 with cells in the ganglion trunci vagi. 



We may therefore sum up our knowledge of the mus- 

 cular innervation of the small intestine in the following way : 

 (i) A set of five medullated fibres leave the medulla in 

 the vagal rootlets, are connected with cells in the ganglion 

 trunci, and then continue as non-medullated fibres straight 

 to the intestinal walls, passing through the solar plexus but 

 not being connected with cells in that plexus. Stimulation 

 of this set causes contraction of both the longitudinal and 

 circular coats. (2) A set of fine medullated fibres arise 

 from the cord, leave by the anterior roots from the sixth 

 thoracic to the first lumbar inclusive, pass through the 

 lateral chain of ganglia and are connected with cells placed 

 chiefly in the superior mesenteric ganglia. Thence they are 

 traced as fine non-medullated fibres to the muscular coats. 

 Stimulation of these fibres causes inhibition of any peris- 

 tallic movements that may be present. At times stimulation 

 has been noted to cause an isolated contraction, often local 

 and of a non-peristallic nature, a contraction which may most 

 reasonably be accounted for as an effect secondary to the 

 contraction of blood-vessels, simultaneously caused by the 

 stimulation. 



^ Arch.f. {Anat. u.) Fhys., suppl., p. 243, 1889. 



^ Loc. cit. 



'^ Journ. of Fhys., vol. vii., p. 19, 1886. 



