THE COLON. 55 



mainly owing to the stagnation of the feecal matters, in conse- 

 quence of the dependent position of this part of the large 

 intestine, and the transverse direction by which the contents of 

 the ileum are discharged into it. ; 



The caecum varies much, however, in different persons, in 

 regard to its length as well as its diameter. 

 - Retentions of the fsecal matter often take place in it, in cases 

 of constipation, which have frequently led to inflammation of 

 this bowel, and to swelling and abscess of the cellular tissue 

 behind it in the iliac fossa or lumbar region. 



The longitudinal bands above mentioned commence at the 

 junction of the appendix with the caecum, and continue through- 

 out the extent of the colon. They appear to be formed by 

 some of the longitudinal fibres of the muscular coat, which are 

 arranged close to each other. These fibres seem to be shorter 

 than the coats of the intestine, and the interior coats adhere 

 firmly to them. Thus are produced the indentations and cells; 

 for if the bands are divided transversely, the indentations dis- 

 appear, and the surface of the intestine becomes uniform. One 

 of these bands is covered by the mesocolon.* 



The circular or transverse fibres of the muscular coat of the 

 cacum and colon are very delicate, and not numerous. 



The internal coat differs materially from that of the small 

 intestines, although at first view they seem to resemble each 

 other ; for if a portion of the ileum and of the colon be inverted 

 and suspended in water, no villi can be seen with the naked 

 eye on the internal coat of the colon, while those of the ileum 

 are very visible. The glands exterior to this coat are larger 

 than those on the small intestines. 



Instead of valvulae conniventes, are the ridges made by the 

 indentations or depressions above described, which separate 

 the incomplete cells from each other. These ridges differ 

 essentially from the valvula3 conniventes, because all the coats 

 of the intestine are concerned in their formation, whereas the 



* In the foetus, no cells are visible in the colon. Their development appears 

 to be owing to the growth of the longitudinal fibres not taking place so rapidly 

 in regard to length, as that of the other coats ; which necessarily causes the 

 crimping of the latter into folds, and the formation of cells. p. 



