MOVEMENTS OF THE LARGE INTESTINE. 267 



food, cholesterine will be found in the faeces, although, for a few days, ster- 

 corine is also present. It is a fact generally recognized by those who have 

 analyzed the faeces, that cholesterine does not exist in the normal evacu- 

 ations; but whenever digestion is arrested, the bile being constantly dis- 

 charged into the duodenum, cholesterine is found in large quantity. For 

 example, in hibernating animals, cholesterine is always present in the faeces. 

 The same is true of the contents of the intestines during foetal life ; the me- 

 conium always containing a large quantity of cholesterine, which disappears 

 from the evacuations when the digestive function becomes established. Ster- 

 corine has not been subjected to ultimate analysis. Its physiological relations 

 will be considered in connection with the excretory office of the liver. 



Indol, Skatol, Phenol etc. The so-called putrefactive processes, which 

 begin in the small intestine, are more marked in the large intestine and give 

 rise to certain products which have the characteristic faecal odor. Certain of 

 these substances may be produced by the prolonged action, out of the body, 

 of the pancreatic juice upon albuminoids. The pancreatic juice, in an alka- 

 line medium, changes the trypsine-peptones into leucine, tyrosine, hypoxan- 

 thine and asparaginic acid. By still farther prolonging this action, indol 

 (C 8 H 7 1S"), skatol (C 9 H 9 N) and phenol (C 6 H 6 0), with some other analogous 

 substances and volatile fatty acids, are formed, and there is an evolution of 

 certain gases. It is probable that these products are formed in abnormal 

 quantities in the small intestine in certain cases of intestinal dyspepsia. 

 The relations of the substances just mentioned to the general process of nu- 

 trition are not understood. 



Movements of the Large Intestine. Movements of the general character 

 noted in the small intestine occur in the large intestine, although the pecul- 

 iarities in the arrangement of the muscular fibres and the more solid consist- 

 ence of the contents render these movements in the large intestine somewhat 

 distinctive. In all instances where the movements have been observed in the 

 human subject or in the lower animals, they have been found to be less vig- 

 orous and rapid than the contractions of the small intestine. Indeed, when 

 the abdominal organs are exposed, either in a living animal or immediately 

 after death, movements of the large intestine are generally not observed, 

 except on the application of mechanical or electric stimulation ; and they are 

 then more circumscribed and much less marked than in any other part of 

 the alimentary canal. That the faeces remain for a considerable time in some 

 of the sacculated pouches of the colon, is evident from the appearance which 

 they sometimes present of having been moulded to the shape of the canal. 

 This appearance is frequently observed in the dejections, which are then said 

 to be "figured." 



In the caecum, the pressure of matters received from the ileum forces the 

 mass onward into the ascending eolon, and the contractions of its muscular 

 fibres are probably slight and inefficient. Once in the colon, it is easy to 

 see how the contractions of the muscular structure the longitudinal bands 

 shortening the canal, and the transverse fibres contracting below and relax- 

 ing above are capable of passing the faecal mass slowly onward. Although 



