FRIEDLANDE&8 BACILLUS. 571 



In man the infection is transmitted to the in- 

 guinal lymph glands, but never becomes general. 



One attack in man does not confer lasting im- 

 munity. Spontaneous recovery occurs, but its 

 cause is not known. Inasmuch as the bacilli are 

 found within leucocytes, phagocytosis may be a 

 factor in recovery. The readiness with which the 

 autoinoculation of adjacent skin takes place, even 

 after the disease has existed for some time, sug- 

 gests that general immunity is not established. 



IX. BACILLUS OF FRIEDLANDER AND OTHER MEM- 

 BERS OF THE CAPSULE-FORMING GROUP. 



The bacillus of Friedlander, or Bacillus pneu- capsuiatea 



. Bacilli. 



momce, is the type 01 a rather large group 01 bac- 

 teria, called the Friedlander group, or the group 

 of Bacillus mucosus capsulatus. In addition to 

 the ability to produce a mucus-like capsule or en- 

 velop, they have in general the following charac- 

 teristics (Abel) : short, plump rods, varying in 

 their proportions, having no motion, no flagella, 

 no spore formation, and not staining by Gram's 

 method. They form mucus-like masses in cul- 

 tures, do not liquefy gelatin and are facultative 

 anaerobes. They are widely distributed in nature, 

 vary from innocuousness to extreme pathogenicity 

 for animals, are rarely found in the mouth, nose 

 and bronchi normally (bacillus of Friedlander), 

 one type being a normal inhabitant of the intes- 

 tines, especially in children (B. laciis aerogenes). 

 Perkins has been able to classify the members of 

 this group on the basis of their fermenting powers 

 for lactose and saccharose. He found their viru- 

 lence for animals, immunization and agglutination 

 tests, too variable to serve as bases for classifica- 



