374 BACTERIOLOGY. 



tions of the throat belonging to both diphtheritic and 

 to non-diphtheritic inflammations which appear exactly 

 alike, having apparently similar symptoms and similar 

 duration; that it is even possible to examine two cases, 

 knowing that one is surely diphtheria, or at least that 

 diphtheria bacilli are present in the exudate, and the 

 other surely is not, and yet be unable to determine 

 clinically which is true diphtheria and which is pseudo- 

 diphtheria. It is not meant to imply that a case is 

 one of true diphtheria simply because the diphtheria 

 bacilli are present, but rather that the doubtful cases 

 not only have the diphtheria bacilli in the exudate, 

 but are capable of giving true characteristic diphtheria 

 to others, or later develop it characteristically them- 

 selves; and that those in whose throats no diphtheria 

 bacilli exist can under no condition give true character- 

 istic diphtheria to others or develop it themselves unless 

 they receive a new infection. It is, indeed, true, as a 

 rule, that cases presenting the appearance of ordinary 

 follicular tonsillitis in adults are not due to the diph- 

 theria bacillus. It is also true that now and then a case 

 having this appearance is one of diphtheria, and almost 

 every physician has seen such cases from time to time 

 in households infected with diphtheria. On the other 

 hand, in small children mild diphtheria very frequently 

 occurs with the semblance of rather severe ordinary 

 follicular tonsillitis, due to the pyogenic cocci, and in 

 large cities where diphtheria is prevalent all such cases 

 must be watched as being more or less suspicious. 

 As showing our doubt in our own judgment, I think 

 most would feel that if in any case exposure to diph- 

 theria is known to have occurred, even a slightly sus- 

 picious sore-throat would be regarded as probably due to 



