254 BACTERIA PATHOGENIC TO MAN 



to be absent in places. Solitary follicles are elevated and enlarged > 

 especially in the region of sigmoid flexure. In some instances the 

 centre of the follicles are depressed and appear to be necrotic. 



Appendix. On section lymphatic follicles are swollen with depressed 

 centres similar to the condition described in the large intestines. 



Small Intestines. Peyer's patches are distinctly swollen, but in no 

 instance is there ulceration or necrosis. 



Large Intestine. Mucous glands are for the most part normal, but 

 over the solitary follicles they have broken down somewhat and con- 

 tain polynuclear leukocytes. The interglandular stroma in these places 

 has undergone necrosis. The necrotic area extends down into the 

 submucosa in the region of the solitary follicles. The capillaries of 

 the solitary follicles are much dilated and congested. The submucosa 

 is thickened and slightly cedematous. The connective-tissue cells appear 

 to have undergone a slight hyaline degeneration. .The musculature is 

 not affected, neither is the peritoneal coat. 



Small Intestines. Normal. 



Historical Notes. In 1897 Shiga found in the stools of cases of 

 dysentery a bacillus which had not been before identified. This 

 bacillus had many of the characteristics of the colon bacillus, but dif- 

 fered from it, lacking motility and failing to produce gas from the 

 fermentation of sugar. It also was entirely distinct in its agglutination 

 characteristics and in its pathogenic properties. Shiga found this 

 bacillus present in all the cases of epidemic dysentery that he exam- 

 ined. It was most abundant during the height of the disease and dis- 

 appeared with the return of fecal stools. It was not found in the stools 

 of healthy persons. He found that the blood of dysenteric patients 

 contained substances which agglutinated the bacilli that he had 

 isolated. The serum from healthy individuals did not agglutinate the 

 bacilli to any such degree as the serum from those sick with dysentery. 

 When the mucous membrane of the colon was examined in fatal cases 

 dying in the height of the disease, the bacilli were found in the super- 

 ficial layers in almost pure cultures. In his hands a serum produced 

 by immunizing horses through injections of dysentery bacilli gave 

 beneficial results when used in the treatment of those ill with the 

 disease. A criminal fed with a culture of the bacillus developed 

 typical dysentery. Certain animals, such as dogs, when subjected to 

 treatment which made them more susceptible, were attacked with 

 dysentery after feeding on cultures. This was fairly similar to that 

 in man. 



Morphological and Cultural Characteristics of Dysentery Bacilli. MICRO- 

 SCOPIC. Similar to bacilli of the colon group. 



STAINING. Similar to bacilli of the colon group. 



MOTILITY. No definite motility has been observed. The molecular 

 movement is very active. 



FLAGELLA. True flagella have not been observed by most examiners. 

 On a very few bacilli in suitable smears Goodwin demonstrated terminal 

 flagella. Spores are not formed. 



