PSEUDOTUBERCULOSIS. 207 



feature is that it grows at temperatures which are fatal to the 

 human tubercle bacillus. This difference may be explained 

 by the fact that as the body temperature of fowls is higher 

 than that of man, the germ may have habituated itself to the 

 higher temperature. 



Pseudotuberculosis. 



This term usually has reference to a pathologic condition, 

 and not to its exciting cause. It is seen in animals, and is 

 characterized by the formation of small nodules resembling 

 tubercles. They are caused by inanimate bodies, animal 

 parasites, bacteria, and highly organized vegetable parasites. 



Bacillus pseudotuberculosis is a short, thick rod, which does 

 not form spores ; stains readily with the anilin dyes, but not 



FIG. 83. 



Smegraa bacilli, similar in appearance to syphilis bacilli. X 1000. (Park.) 



with Gram's solution. It does not liquefy gelatin. In a 

 gelatin stab it grows along the puncture and also on the sur- 

 face of the medium. On agar a heavy gray growth develops. 

 On potato the growth is luxuriant and of a yellowish color. 

 In bouillon the growth gradually settles, leaving the super- 

 natant fluid clear and transparent. The bacillus is pathogenic 

 for animals, especially mice, rats, and guinea-pigs. 



Various streptothrices and Aspergillus glaucu$ and A.fumi- 

 gatus have also been found in these pseudotubercles. 



