314 SPECIFIC MICRO-ORGANISMS 



of the skin where there are collections of moist desquamated 

 epithelium. It resembles the tubercle bacillus in form and stain- 

 ing properties, but is, on the average, more readily decolorized in 

 alcohol. This property cannot be relied upon to differentiate 

 the two organisms in any given case. Proper care in collecting 

 specimens for examination usually suffices to exclude this or- 

 ganism. Urines to be examined for tubercle bacilli should be 

 obtained by catheter. In doubtful cases inoculation of a guinea- 

 pig is necessary. B. smegmatis has been grown in artificial culture 

 and after a time adapts itself to ordinary media. 



Bacillus Moelleri. Acid-proof organisms resembling the 

 tubercle bacillus in form and staining properties were found on 

 timothy hay by Moeller. The bacillus is likely to be found in 

 milk and other dairy products. Probably the " butter bacillus" 

 of Rabinowitsch is identical with it or a near relative. When 

 introduced into guinea-pigs these organisms sometimes produce 

 lesions resembling tubercles, but these do not progress and kill 

 the animal and a second animal inoculated from the lesions of the 

 first gives a negative result. Cultures are easily, obtained on 

 ordinary media, and the organisms grow rapidly at 25 to 30 C. 



Other Acid-proof Organisms. Many of the strep to thrices 

 which grow in the soil and upon plants are to some extent similar 

 in their staining properties to the tubercle bacillus and when 

 broken up into short segments may be a source of confusion. 

 These are most likely to be met with in examining agricultural 

 products and especially in the feces of cattle. Mere microscopic 

 examination of such materials for tubercle bacilli has, as a rule, 

 little value, as both positive and negative findings are question- 

 ->able. Brem, 1 in the Canal Zone, has made the important obser- 

 vation that acid-proof bacilli may grow in distilled water stored 

 in bottles in the laboratory and that, when such water is used in 

 preparing the microscopic objects for examination," these extrane- 

 ous bacilli may be mistaken for tubercle bacilli. Burvill-Holmes 2 



1 Journ. A. M. A., 1909, Vol. LIU, pp. 909-911. 



2 Proc. Path. Soc. Phila., 1910, N. S. Vol. XIII, pp. 154-160. 



