THE XEROSIS BACILLUS 297 



Fusiform bacilli have been met with in various necrotic pro- 

 cesses, e.g. noma (see Chapter XX). 



The Xerosis Bacillus 



The xerosis bacillus was isolated by Neisser from cases of xerosis 

 conjunctives, and is met with in follicular conjunctivitis. Lawson 

 and also Griffith isolated it from nearly 50 per cent, of all normal 

 conjunctival sacs. In morphology and staining reactions it re- 

 sembles the Klebs-Loffler bacillus very closely. It differs from the 

 Klebs-Loffier bacillus in the following particulars : (1) Usually, 

 but not always, in the primary cultivations from the eye on blood- 

 serum, colonies do not appear under about thirty hours, while 

 those of the Klebs-Loffler bacillus are visible in sixteen to twenty 

 hours. This does not apply to the secondary cultivations, in which 

 the colonies appear as soon as those of the Klebs-Loffler bacillus. 



(2) Upon agar it will seldom or never grow in primary culture, and 

 in secondary cultures it forms only a thin, translucent, dry film. 



(3) Upon gelatin it will never grow in primary culture and seldom 

 in secondary culture. (4) It does not give rise to acid production 

 in milk or glucose broth. (5) It is non-pathogenic to guinea-pigs. 

 (6) The Neisser stain is negative. The fermentation reactions will 

 be found in the Table on p. 292. 



In all probability the organism is not causative of xerosis con- 

 junctivse. 



To isolate the organism, blood-serum tubes are inoculated with 

 a looped platinum needle from cases of follicular conjunctivitis or 

 xerosis and incubated at 37 C. for forty to forty-ei ght hours. 

 Half the tubes will usually show a growth. Preparations may be 

 stained with Loffler's blue and by Gram's method. 



Bacillus coryzae (segmentosus) 



An organism first described by Cautley, of frequent occurrence 

 in the nasal secretion in cases of " influenza " cold. It bears a 

 striking resemblance morphologically to the B. diphtheria when 

 stained with methylene blue, and is Gram -positive, but does not 

 show granules either with Loffler blue or with Neisser's stain. On 

 agar it grows more slowly than B. diphtherice, and in glucose broth 

 and litmus milk acid production is slow and feeble. It is non- 

 pathogenic to guinea-pigs. The fermentation reactions will be 

 found in the Table on p. 292. 



