Upon the Pseudo- Diphtheria, etc. 25 



was the same where the antitoxin serum was injected 

 before, at the same time, or after the injection of the 

 culture. He again states his belief that it is not unlikely 

 that the so-called xerosis bacilli are nothing else than true 

 diphtheria bacilli robbed of their virulence. 



Eyre (24) sums up his investigations by stating that " in 

 differentiating the xerosis bacillus from the L,6ffler bacillus 

 we are saved all trouble in the case of first cultures by the 

 fact that the former does not grow on blood serum at 37 C. 

 under thirty-six to forty-eight hours, whilst the latter makes 

 its appearance in eighteen to twenty-four hours. At the 

 other extreme, with cultures some fifteen to twenty gen- 

 erations old, there is likewise very little difficulty in dis- 

 tinguishing between these two organisms, as the xerosis 

 bacillus then appears as a much shorter, more slender and 

 more curved bacillus, exhibiting neither segmentation nor 

 clubbing. But in the case of early sub-cultures from the 

 first culture, the circumstances are entirely altered, and we 

 have to deal with an organism closely resembling in its 

 general characters and mode of growth the L,6fHer bacillus 

 an organism moreover which has no one single persistent 

 peculiarity which will enable us to say definitely, this is 

 the xerosis bacillus. We have therefore to depend upon 

 the sum total of the cultural and morphological differences 

 minute in themselves picked out during the course of 

 numerous observations. 



As to the exact nature of the xerosis bacillus whether 

 it be a non-virulent and slightly altered species of the 

 bacillus diphtheriae or a totally separate and distinct 

 bacillus it is impossible at present to decide. 



Schanz (25) reports that in ten normal conjunctival sacs 

 he found the xerosis bacillus four times ; finding it to be 

 the most frequent organism of the conjunctival sac. In 

 comparing one derived from a case of xerosis with kera- 

 tomalacia with the Loffler bacillus, he found that a certain 

 differentiation of the two organisms could not be made, on 



