196 DIGESTION. [CHAP. xxiv. 



ments of the intestinal canal, which indeed appear, as it were, to 

 start from the junction of this portion of the stomach with its car- 

 diac portion. Under the influence of the magneto-electric appa- 

 ratus this mode of contraction of the pyloric fibres may be well 

 shewn in dogs or cats just dead, and the contrast with the action of 

 the cardiac fibres may be strikingly displayed. 



We had lately an opportunity of observing the peristaltic 

 character of the movement of the pyloric portion of the stomach 

 during life, in a woman in whom that organ was so enor- 

 mously enlarged as to occupy nearly the entire abdominal cavity, 

 the intestines being pushed into the pelvis, and the arch of the 

 colon lying behind the stomach. The patient was so emaciated, 

 and the abdominal parietes so attenuated, that the action of the 

 viscus could be distinctly seen through them ; and it appeared to 

 resemble precisely the vermicular action of the intestines, for which, 

 indeed, it was taken, as the nature of the case could not be dis- 

 tinctly recognized during life. 



When the action of the stomach is energetic, a constriction is 

 produced, by which the pyloric third is separated from the cardiac 

 portion, thus giving rise to the hour-glass contraction, which con- 

 tinues for some time after death if the animals have been killed at 

 the moment of its occurrence. The same condition may be produced 

 by the magneto-electric apparatus. This constriction has been 

 noticed by all observers in dogs and cats, and may be now and 

 then seen in the human stomach. In some animals such a division 

 between the two portions of the stomach exists in the natural 

 conformation of the organ. 



The muscular action of the stomach in man and the mammalia 

 seems merely to push on the food into the intestine, and not to 

 subject it to any trituration or mechanical reduction, according to 

 the view of the physiologists of the early part of the last century. 

 Reaumur, and after him Spallanzani, introduced into the stomachs 

 of dogs and cats perforated tubes, made some of brittle and others 

 of flexible materials. These were found quite unaltered by the 

 action of the stomach, although the portions of food contained in 

 them were softened and digested. 



2. Changes in the Mucous Membrane of the Stomach. The gastric 

 mucous membrane of the stomach of an animal killed during 

 stomach digestion exhibits a faintish red and swollen appearance, 

 due evidently to an increased afflux of blood, excited by the stimulus 

 of the food. In the dog this redness is limited in a very marked 

 manner to the splenic two-thirds, the pyloric third presenting a 



