MOVEMENTS OP THE LAKGE INTESTINE. 405 



times seen on opening the abdomen immediately after death 

 are feeble and irregular, particularly in the caecum. That 

 the faeces remain for a considerable time in some of the sac- 

 culated 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 ob- 

 served in the dejections, which are then said to be " fig- 

 ured." 



In the caecum, the pressure of matters received from the 

 ileum forces the mass onward into the ascending colon, and 

 the contractions of its muscular fibres are undoubtedly slight 

 and ineffective. 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 relaxing above) are capable of passing the faecal 

 mass slowly onward. Though the transverse fibres are thin 

 and seemingly of little power, they are undoubtedly power- 

 ful enough to empty the sacculi, when assisted by the move- 

 ments of the longitudinal fibres, especially as the canal is 

 never completely filled and the fasces are frequently in the 

 form of small moulded lumps. 



By these slow and gradual movements, the contents of 

 the large intestine are passed toward the sigmoid flexure of 

 the colon, where they are arrested until the period arrives 

 for their final discharge. The time occupied in the passage 

 of the faeces through the ascending, transverse, and descend- 

 ing colon is undoubtedly variable in different persons, as we 

 find great variations in the intervals between the acts of 

 defecation. During their passage along the colon, the con- 

 tents of the canal assume more and more of the normal 

 faecal consistence and odor, and become slightly coated with 

 the mucous secretion of the parts. 



It has been pretty conclusively shown that the accumula- 

 tion of faeces generally takes place in the sigmoid flexure ; for 

 under normal conditions, the rectum is found empty and con- 

 tracted. This part of the colon is much more movable than 



