He BiINGiIONS OF THE VISCERAL NERVES Ope 
of this point were afterwards made upon a rabbit which had died of haemorrhage 
C 
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.t Professor Goodsir gave me the first information 
of the anatomical fact on my mentioning to him the foregoing physiological 
proofs of the existence within the intestines of a co-ordinating 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 co-ordinating power in the 
intestines, the latter lasts much longer than the inhibiting property in the 
spinal system, for I find that Pfliiger’s experiment does not succeed in a dead 
animal, unless performed soon after death, although the intestines may continue 
to move for a long time. 
In another experiment I divided with fine scissors, at a little distance 
from the intestine, all the visible branches of nerves in a portion of mesentery 
corresponding to an inch and three-quarters of the gut, leaving the vessels 
uninjured. No effect was produced on the peristaltic movements, which hap- 
pened to be pretty active at the time, and continued the same at the seat of 
the operation as elsewhere. To ascertain whether the division of the nerves 
had been thoroughly effected, I now transmitted powerful galvanic currents 
through the spine, as in former experiments, when all movements ceased in 
the intestine, except in the small piece whose nerves had been cut, which 
continued in vigorous action as before. The persistence of the vermicular 
motion after complete division of the mesenteric nerves shows that the move- 
ment which occurs during life, ike that which takes place post mortem, 1s effected 
by a mechanism within the intestine; and its continuance in the portion of 
gut so treated, while other parts were relaxed, on the application of galvanism 
to the spine, proves that the inhibiting influence acts through the mesenteric 
nerves, whose integrity is necessary to the effect. 
This being established, it follows that if a quiet state of the intestine, 
such as very frequently occurs in its natural condition, were due to a con- 
trolling agency on the part of the so-called ‘ inhibitory system’, the complete 
division of the mesenteric nerves supplying a portion of gut which is at rest, 
would liberate it from this restraint, and movement would be the result. I per- 
formed the operation in one case under such circumstances, but the portion ot 
intestine concerned remained as tranquil as the rest. 
1 Henle and Pfeufer’s Zeztschrift, 2nd series, vol. vill. 
