142 



BACTERIOLOGY OF THE EYE 



peptone agar * and 1 part of ascitic fluid, containing sheep's or human blood in the 



proportion of 1 to 2. Hofmann could not obtain cultures on simple agar with human 



blood added. 



Kamen and Markus obtained very good results with Pfeiffer's blood media 



(human blood), on which they were able to grow the bacilli with certainty and for 



many generations. They did not use pure serum agar. 



Weichselbaum and Miiller at first stated that the Koch-Weeks bacillus would 



only grow on serum agar ; later they obtained cultures on blood media from 



a few cases. 



The different epidemics seem to vary somewhat in regard to culture peculiarities. 



Kamen's and Markus's cases were very acute and severe, considerably more so than 



those of the epidemic observed by 

 Weichselbaum and Miiller, or Hof- 

 mann's cases. The media and the 

 blood used are not always the same. 

 Considering all the records together, 

 we find that the Koch-Weeks bacillus 

 grows best on serum agar or in 

 serum bouillon; but that it can be 

 grown on blood media, though this 

 method is not so certain in all 

 epidemics. Regarding its relation- 

 ship to the influenza bacillus, it 

 should be noted that human (not 

 pigeon's) blood only should be 

 used. 



Luerssen reported, however, that 

 he had succeeded in growing a strain 

 of Koch-Weeks beyond the fiftieth 

 generation on pigeon's-blood agar, 

 and that without any assisting 

 organism being present, He con- 

 sidered the Koch -Weeks bacillus as 

 one of the Haemophile group, and 



put it in the same class with the influenza bacillus, although quite distinct from that 



organism. Zur Nedden considers that the human serum which is obtained with 



the blood makes the cultures possible. 



The bacilli are rarely obtained in pure culture ; they are generally 

 accompanied by xerose bacilli, and often by a few Staphylococci, As 

 has been stated by Eymowitsch, Usher and Fraser, and as I have 

 myself determined, the simultaneous presence in the cultures of xerose 

 bacilli, of diphtheria bacilli, or of Staphylococci, favours the growth 

 of the Koch-Weeks bacillus. 2 Weichselbaum and Miiller stated that 

 the same was true for the so-called ' Luft-keime ' (following the view 

 of Grassberger in so naming the staphylococcal group). Usher and 

 Fraser found that growth was favoured by the presence of the Diplo- 

 bacillus, and that stems of the Koch-Weeks, which could not be further 



1 Kamen could not get any growth on this. 



2 In a similar way the xerose bacilli favour the growth of the influenza bacillus 

 (M. Neisser), with which the Rymowitsch bacillus should be considered as identical. 



FIG. 14. KOCH-WEEKS CULTURE ON 

 BLOOD AGAR (KAMEN). 



The large colonies are Staphylococci. 



