

ON INTESTINAL SECRETION. 309 



semilunar ganglia and solar plexus, or division of the mesenteric nerves 

 themselves. 



5. The splanchnic nerves are, as usually admitted, the vasomotor nerves of 

 the intestines, but have no centrifugal fibres to their muscular coats, and 

 can only indirectly affect them by diminishing their supply of blood. 



(5. The splanchuics are the afferent nerves which regulate peristalsis of the 

 intestine, the efferent stimulus probably reaching its intraparietal ganglia 

 through the lumbar cord and abdominal sj-mpathetic. 



The following are the details of the experiments made this year. With 

 those described in our two preceding Reports, they make up a total of more 

 than a hundred, as the basis of the above conclusions. 



In the first series we continued and completed the experiments in our last 

 Report, undertaken to ascertain the nervous centre, separation from which 

 produces the " paralytic " secretion of Moreau. Starting from the negative 

 results with which we concluded our research last year, it will be seen that, 

 of the thirteen cases in which we removed the solar or the superior mesenteric 

 plexus, paralytic secretion resulted abiuidantly in Nos. 1, 2, 3, and 13, where 

 both Avere removed. Tlie same effect was produced in Nos. 7, 8, and 10, 

 whero the splanchuics and semilunar ganglia were left intact, and only the 

 smaller (inferior) ganglia of the solar plexus, with the superior mesenteric 

 offset from it, were excised. In No. 5, and also in No. 14, the paralytic 

 secretion was likewise present, though less abundant. In four cases 

 (Nos. 4, 6, 9, and 11) there was little or none; but in three of these 

 cases the dissection, by which we verified in each case the completeness of 

 the lesion produced, showed that the plexus had only been torn away from 

 the artery without complete excision of its ganglia ; and in No. 11 the superior 

 mesenteric plexus was simply cut across, so as to separate it from the semi- 

 lunar ganglia and splanchuics, with the superior part of the solar plexus. Thus 

 the negative results here, like those of last year's experiments, confirm 

 our present conclusions. In No. 12 there was enough fiuid foimd to 

 fill the loop moderately, but the rest of the intestine was empty : dis- 

 section did not show any defect in the previous operation, nor had there 

 been htemorrhage, diarrhoea, or sickness. It will, however, be noted that in 

 this experiment less time Lad elapsed than in any of the others (2 instead of 

 3|, 4, 5, or (3 hours) ; and this fact, taken with the observation of the most 

 abundant secretion having followed the longest period between the excision 

 of the plexus and the animal being killed (see No. 7), may perhaps explain 

 the scanty secretion in this instance. 



The concluding series of experiments are on a diflicult subject, which has 

 already engaged the attention of Ludwig and his pupils, of Lister, Pfiiiger, 

 Wundt, Von Basch, and other distinguished physiologists. AVhether we are 

 justified in the conclusions which we have drawn we must wait for time to 

 determine, and will only add that we are well aware of the many possible 

 fallacies which attend the inquiry, as well as of the conflicting results of 

 previous investigators. 



p.y. — Since this Report was presented (Glasgow, 1870), one of us, who was 

 fortunate in securing the requisite Certificate from the Home Oflice, has 

 obtained fresh results confirming those of the second series of these experi- 

 ments. — July 1877. 



