704 PATHOGENIC MICROORGANISMS 



to agglutinate as highly at 1 : 320, while the other three cultures gave 

 no reaction in dilutions of over 1 : 10 or 20. 



Park and Carey, 13 in March, 1903, described an epidemic of dysen- 

 tery occurring in the town of Tuckahoe, near New York city, and 

 isolated an organism which resembled the Shiga-Kruse bacilli in not 

 fermenting mannit, but produced indol in pepton solution after five 

 days. It corresponded in agglutination with the cultures "New 

 Haven" and "Shiga" when tested in the serum of a goat immunized 

 against the mannit-fermenting culture "Baltimore," i.e., did not react 

 at 1 : 50, whereas Flexner's "Manila" and "Baltimore" cultures, Park 

 and Dunham's "Seal Harbor" culture, and some New York cultures, all 

 fermenting mannit, agglutinated up to two thousand dilution in the 

 "Baltimore" serum. 



The preceding review of a part of the literature, by which our knowl- 

 edge of the dysentery bacilli was developed, demonstrates sufficiently 

 that we have to deal in this group with a number of different micro- 

 organisms. This, as we have seen, was a fact first recognized by Kruse 

 when he spoke of his true dysentery and his pseudo-dysentery strains. 

 In spite of much confusion at first, the careful study of fermentation 

 phenomena, of specific agglutinations, and, more recently, by Ohno 14 

 and others of the bacteriolytic phenomena in immune sera, has made 

 it possible to distinguish sharply between a number of groups. 



Basing the grouping of these microorganisms upon a careful study of 



fermentations, Hiss 15 has divided them as follows: 



* 



"Shiga" 



"Kruse" \ Ferment dextrose. Group I. 



"New Haven" 



"Y" (Hiss and Russell type) 



"Seal Harbor " Ferment dextrose and mannit. Group II. 



"Diamond" 



"Ferra" 



''Strong" (type) Ferments dextrose, mannit, saccharose. Group III. 



rns ( ypi Ferment dextrose, mannit, maltose, saccharose, 



dextrin. Fermentation of saccharose (as a rule) 



only after six days. Group IV. 

 "Wollenstem" 



It was noticed, it should be mentioned, however, that in the case of the 



13 Park and Carey, Jour. Med. Res., ix, 1903. 



14 Ohno, Philippine Jour, of Sci., 1, ix., 1906. 



15 Hiss, Jour. Med. Res., N! S., viii, 1904. 



