262 BACTERIA PATHOGENIC TO MAN 



by Shiga, and give the name paradysentery to the other two groups 

 which approach more closely the colon group in that they produce 

 indol and have a greater range of activity in fermenting carbohydrates. 

 An additional reason for the use of the prefix para, beyond that of 

 convenience, is the less average severity of the disease due to these 

 types, and the probability that there will be found, in occasional sporadic 

 cases and epidemics of dysentery, bacilli which have a causal relation 

 to dysentery and exhibit more pronounced characteristics of the colon 

 group than any of .the varieties so far isolated. 



