220 



and Hammerschmidt believe that the two organisms are very 

 different, while Davis (6) looks upon them as practically the 

 same, only, however, on the basis of investigations of a single 

 character (symbiosis). 



Unfortunately it has not been possible for me to investigate 

 this organism because the epidemic conjunctivitis in which 

 it is found does not occur in this country, and I have tried 

 in vain to obtain cultures elsewhere. Moreover for a pro pel- 

 comparison with Pfeiffer's bacillus one must have the oppor- 

 tunily of collecting a large amount of material of both bac- 

 teria directly from their natural habitats. 



From my experience of the nutritive demands of Pfeiffer's 

 bacillus however, the bare fact that several authors emphati- 

 cally state that it grows better on ascitic and hydrocele agar 

 than on haemoglobin-containing media (e. g. Levinthal agar 

 and pigeon blood agar), is in my opinion sufficient proof tnat 

 the Koch-Weeks' bacillus and Pfeiffer's bacillus cannot be 

 regarded as identical. It is curious nevertheless that the sym- 

 biosis phenomenon is present in the case of both organisms (in 

 the same form?). 



In connection with the Koch-Weeks' bacillus, Mc Kee's 

 bacillus must be mentioned which has the following points of 

 similarity with it: it was found to cause conjunctivitis; it is 

 not very haemoglobinophilic (it can be cultivated on haemoglo- 

 bin agar or on haemoglobin-free media); and its growth is 

 increased by other bacteria. It grows more slowly and feebly 

 than Pfeiffer's bacillus on haemoglobin agar. 



It is clear that when the term „haemoglobinophilic bacteria" 

 is used so loosely that all the organisms which have been 

 referred to here are included, it is a matter of indifference 

 where the line is drawn. We will therefore take the expression 

 „haemoglobinophilia" literally and only include organisms with 

 food requirements similar to Pfeiffer's bacillus and B. haemo- 

 globinophilus canis. 



Of the organisms which have been termed by different 

 authors „infiuenza bacillus-like", the following immediately fall 

 out of line: 



Beck's, Kraus', Volk's and Kurita's bacilli from rabbits; 



Frank's bacillus from swine; 



Bacillus bronchicanis (bronchisepticus) (Ferry); 



