

371 



injury to the adjacent nervous branches ; and it therefore followed 

 that the movement in the parts supplied by those vessels was not 

 due to any injury of the nerves, but simply to the arrest of circula- 

 tion. It further appears from these experiments, that, in whatever 

 way the cessation of the flow of blood through the vessels operates 

 in increasing the peristaltic action, it does so through the medium of 

 the nervous apparatus, and not by directly influencing the muscular 

 tissue. For, in the latter case, the movement would have continued 

 in spite of the inhibiting influence, which, as we have seen, has no 

 effect upon muscular irritability. 



The fact that the movements continue in a portion of gut deprived 

 of its mesentery, proves that the nervous apparatus by which the 

 muscular contractions are induced and coordinated in post mortem 

 peristaltic action, is contained within the intestine. 



The distinction between the coordinating power and muscular 

 contractility was very strikingly shown in the further progress of one 

 of these experiments. The peristaltic movements of the portion of 

 gut supplied by the ligatured arteries ceased entirely about twenty 

 minutes after the vessels were tied, and the surface of the gut be- 

 came there perfectly smooth and relaxed, contrasting strongly with 

 the wrinkled aspect of other parts. But muscular irritability had 

 outlived the coordinating power, as was shown by energetic, purely 

 local contraction taking place in a part pinched. Similar observa- 

 tions confirmatory of this point were afterwards made upon a rabbit 

 which had died of haemorrhage an hour before. 



The mechanism by which the muscular contractions are regulated 

 is, doubtless, the rich ganglionic structure lately demonstrated in 

 the submucous tissue by Dr. Meissner of Bale * . Professor Goodsir 

 gave me the first information of this anatomical fact on my men- 

 tioning to him the foregoing physiological proofs of the existence 

 within the intestines of a coordinating apparatus distinct from the 

 muscular tissue. I have since verified Meissner' s observations, and 

 found abundant well-marked nerve-cells in the submucous tissue of 

 the Ox, exactly corresponding with his descriptions. 



But while muscular irritability outlives the coordinating power 

 in the intestines, the latter lasts much longer than the inhibiting 



* Henle and Pfeufer's Zeitschr. 2nd series, vol. viii. 



