BACILLUS DYSENTERIC. 469 



as dextrose. The Shiga type ferments dextrose, but 

 none of the other carbohydrates. 



THE STRONG TYPE OF ORGANISM. This type of 

 organism has many of the characters of the Harris type, 

 though it ferments only mannite, dextrose, and saccha- 

 rose. 



THE HARRIS TYPE OF ORGANISM. This type of 

 bacillus dysenterise was first encountered by Strong 

 while working in the Philippine Islands. It has since 

 been encountered quite frequently in the United States, 

 especially in the summer diarrhoeas in infants. This 

 organism ferments mannite as well as dextrose, maltose, 

 saccharose, and dextrin. 



It is only by careful observations of the reactions 

 with the different carbohydrates that it is possible to 

 differentiate between these different types of bacillus 

 dysenteriae, as has been shown by Hiss 1 and by others. 



THE AGGLUTINABILITY OF BACILLUS DYSENTERIC. 

 The study of the influence of the agglutinins in dys- 

 entery immune serum has also served to differentiate 

 between different types, of bacillus dysenterise. Normal 

 serums, especially those of bovines and of goats, also 

 yield very instructive results. These variations in the 

 agglutinability of the several types of bacillus dysenterise, 

 especially in normal serums, were first pointed out by 

 Bergey, 2 and have since been substantiated by many 

 other investigators (see especially Park and Hiss, loo. ciL). 



The different types of bacillus dysenterise can easily 

 be distinguished by their relative agglutinability. In 

 order to bring out the relative influence of the immune 

 serum upon each variety of bacillus dysenterise it is 



1 Hiss : Journal of Medical Research, vol. viii., Dec., 1904. 



2 Bergey: Journal of Medical Research, 1903, vol. v,, p. 21. 



