560 THE DIGESTIVE SYSTEM. 



suppurative and necrotic lesions of the ileum and colon ; Streptococcus 

 pyogenes, Staphylococcus pyogenes, Bacillus coli commuuis, Bacillus 

 proteus, Bacillus pyogenes, and others. The significance of these organ- 

 isms is not yet clear. ' 



Mucous Colitis (Membranous Colitis). Under a variety of obscure con- 

 ditions, probably sometimes inflammatory in character, shreds or sheets 

 or" even cylindrical casts of the interior of the gut are passed from the 

 bowels. These consist of dense mucus often mingled with degenerated 

 epithelium. 2 



Chronic Colitis. In prolonged inflammation of the colon marked struc- 

 tural alterations may take place. The glandular coat may be uniformly 



FIG. 337. CHRONIC COLITIS WITH EXTENSIVE ULCKRATION OF THE Mucous MEMBRANE. 



in places only a few ragged Islets of mucous membrane are left, the muscularis forming the bottom of the 



ulcers. 



thickened, or thrown into the form of polypoid tumors, or atrophied, or 

 destroyed by ulcers of various sizes and shapes (Fig. 337). Small cysts 

 may form from the retention of mucus in the follicles. The connective- 

 tissue and muscular coats may be thickened or thinned. Apparently 

 chronic colitis may follow any of the forms of acute colitis. 



Eepair may follow even considerable losses of substance in the intes- 

 tinal mucous membrane. The new-formed connective tissue may under- 

 go slight or marked cicatricial contraction. The denuded surfaces may 

 become covered anew with epithelium derived from the intact cells. 3 



1 See Krute and Pnsquale, Zeits. f. Hygiene und Infkr., Bd. xvi., p. 1, 1894; also 

 Ceremille, Tavel, and others, Ann. Suisses des Sc. Med., ser. ii., p. 531, 1895. 



See for consideration of Streptococcus enteritidis in infants, Hirsch, Centralbl. f. 

 Bak., AbtJi. I., Bd. xxii., p. 369, bibliography. 



For a study of intestinal bacteria see Lembke, Arch. f. Hygiene, Bd. xxvi., p. 293, 

 1896, bibl. ; also Mace's "Bacteriologie," 1901, p. 1140 etseq.; Kohlbrugfje, Centralbl. 

 f. Bak. (I. Abth.), Bd. xxx., 1901, pp. 10 and 70; Ford, "Studies Royal Victoria Hos- 

 pital," Montreal, vol. i., 1903, resume and bibl. 



* Numerous observations have been made and a large bibliography has been gath- 

 ered on what is called membranous enteritis or colitis, for which the reader may consult 

 Butler, New York Medical Journal, December 28th, 1895, or Akerlund, Arch. f. Ver- 

 dauungskrankheiten, Bd. i., p. 396, 1896. 



3 For study of regeneration of intestinal epithelium see Quemt and Branca, Arch. d = 

 Med. exp., vol. xiv.. 1902, p. 405. 



