26o MANUAL OF BACTERIOLOGY. 



cular thickening and swelling of the skin around the nose and 

 similar swelling of the nasal mucous membrane, sometimes 

 followed by ulceration. It is commonest in Austria and Italy. 

 It has been seen in America only very rarely. 



The organisms may be stained in the diseased tissues, but 

 their detection is a matter of considerable difficulty, and they 

 are not always found. It is not yet certain that they are the 

 cause of rhinoscleroma. 



Bacillus mycogenes.* — A plump, short bacillus, less than 

 1 fj-in breadth, possessing no flagella, non-motile, does not form 

 spores; capsules are seen in preparations from tissues of inocu- 

 lated animals and in milk cultures, rarely in preparations from 

 agar cultures. The organism occurs singly or in pairs, and 

 even in longer filaments. Gram positive in tissues, but nega- 

 tive in cultures. 



The growth on agar is porcelain white and viscid. In all 

 liquid media viscidity is very marked. Gelatin is not liquefied. 

 Coagulated blood-serum not liquefied. "Nail-head" growth 

 shows in stab cultures. Milk is coagulated in one to five 

 days. Casein not digested. Litmus is reduced. Growth on 

 potato is brown and slimy, but there is no gas formation. 

 Indol negative. None of the sugars are fermented. 



Very pathogenic for rabbits and guinea-pigs. Rabbits are 

 killed in eighteen hours by subcutaneous injection of y^-g- c.c. 

 of a twenty-four hour beef-brOth culture, guinea-pigs in less 

 than fifteen hours by the same dose. 



Bacillus pyocyaneus. — A slim bacillus with rounded ends. 

 It is motile. It does not form spores. At 56° C. it is killed 

 in ten minutes. It is decolorized by Gram's method. It is 

 aerobic; grows well at ordinary temperatures; liquefies gelatin, 

 and grows on the ordinary culture-media. Cultures present 



* Ralph T. Edwards. Journal of Infectious Diseases. Vol. II. No. 

 1905. 



