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BIOLOGICAL PHYSICS 



undigested residuum is passed through the ileo-caecal 

 valve, to be subjected to a still farther digestive process, 

 ere it is ejected, as altogether indigestible. 



Posterior to the ileo-caecal valve (Fig. 115), the 

 intestinal canal is continued as the larger bowel, con- 

 sisting of the caecum, with the vermiform process, 

 colon, and rectum, to the anus, where the division, and 

 differentiation, of the neurenteric canal, were originally 

 effected, and where the residual result, of the various 

 digestive processes, to which the elements of the food 

 originally ingested have been subjected, are ultimately 

 ejected. The digestive processes, to which the contents 

 of the larger bowel are subjected, seem to be, in principle, 

 and method, a continuation, and completion, of the long 



FIG. 114. POKTIOX OF SMALL INTESTINE LAID OPEN TO SHOW THE 

 VALVULAR CONNIVENTES. (Brinton.) 



series constituting the physiologically entire process of 

 digestion, and, as is characteristic of the preceding stages, 

 they are conducted with " closed doors," the ileo-caecal 

 valve, the sigmoid flexure, to some extent, and the anus, 

 constituting barriers, which, in the physiologically healthy 

 condition, are effective barriers. 



From this point of view, we think we are warranted in 

 regarding the caecum as a posterior stomach, in which the 

 residual chylous contents of the smaller bowel are sub- 

 jected, on their arrival, to a further muscular agitation, 

 during their admixture with the secretion of the vermiform 

 process, a lymphoid material, which is credited with 

 almost negligible qualities, but, nevertheless, a secretion, 

 of as definite, and physiologically decided a character, as 

 those of the liver, and pancreas, and the only secretion, 

 moreover, which empties itself into the commencement of 



