588 AFFECTIONS OF THE INTESTINAL CANAL. 



portion is constantly driven deeper in, and the inversion becomes more 

 complete. Intussusception is found in both the small and large intes 

 tine. The lower end of the small intestine not unfrequently enters 

 the large intestine ; and cases have been observed where the ileo-caecal 

 valve was close to, or even projected out of, the anus. Intussuscep- 

 tions mostly occur in the course of chronic diarrhoeas ; it is most prob- 

 able that they are caused by a portion of intestine contracting strongly, 

 and, by elongating and moving forward at the same time, entering the 

 non-contracted portion just below ; part of the latter is drawn along 

 and inverted with the contracted portion. New peristaltic movements 

 force the invaginated portion of intestine farther and farther into the 

 outer portion, until the resistance from the mesentery, or the adhesion 

 of the parts pushed into one another, arrests the progress of the inner 

 portion. Occasionally, particularly in the bodies of children who have 

 died of hydrocephalus, we often find one or more intussusceptions, 

 which are usually short ; these have occurred during the death-agony, 

 as is shown by the absence of all signs of inflammation. They alsc 

 appear to be caused by increased and unequal contraction of the intes- 

 tines, by which the contracted portions are forced into the larger. It 

 is worthy of remark that increased movements of the intestines, which 

 may even be perceived through the abdominal walls, are seen just be- 

 fore death in animals, even after paralysis of the cerebro-spinal system 

 has occurred. 



6. Finally, the intestines may be closed by extensive accumulations 

 of hard and dry faeces, or by stony concretions consisting of hardened 

 faeces, or precipitates of the triple phosphates and lime-salts. This form 

 of closure may be just as complete, and the symptoms during life may be 

 just as threatening, as in those caused by rotation of the intestine on its 

 axis, by internal strangulation, or by imagination. Cases where fecal 

 vomiting and obstinate constipation were overcome by large doses of 

 metallic mercury and similar remedies are not to be blindly taken as 

 examples of cures of internal strangulated hernia, etc., but rather prove 

 that retained fasces may excite the combination of symptoms, which is 

 usually designated as ileus or miserere. Complete closure of the in- 

 testines by masses of faeces occurs most readily at those places where 

 mechanical obstructions constantly oppose and retard the progress of 

 the contents of the intestines ; hence it is more likely to take place 

 above the bent portions and the adhesions, of which we spoke in a 

 previous chapter, above compressed portions, or above the various 

 forms of stricture of the intestine. In other cases a sub-paralytic state 

 of the intestinal muscles, or a diminution of the secretion from the in- 

 testinal mucous membrane, appears to favor the collection of the ob- 

 structing fneces. Lastly, the use of food which forms a great quantity 



