286 TUBEKCULOSIS 



'with some difficulty and resists decolorisation with strong mineral acids. 

 Most observers ascribe the latter facf to the fatty matter with which it 

 is surrounded, and find that if the specimen is treated with alcohol 

 the organism is easily decolorised. Czaplewski, however, who has culti- 

 vated it on various media, finds that in culture it shows resistance to 

 decolorisation both with alcohol and with acids, and considers, therefore, 

 that the reaction is not due to the surrounding fatty medium. We 

 have found that in smegma it can be readily decolorised by a minute's 

 exposure to alcohol after the usual treatment with sulphuric acid, and 

 thus it can be readily distinguished from the tubercle bacillus. We, 

 moreover, believe that minor points of difference in the microscopic 

 •appearances of the two organisms are quite sufficient to make the 

 experienced observer suspicious if he should meet with the smegma 



bacillus in urine, and lead 



/ • . him to apply the decolorising 



» test. Difficulty will only 



A ' "S \~" \ occur when a few scattered 



/ , j> bacilli retaining the fuchsin 



/ C^ \f _ \ are found. 



I " ' a > ' Its cultivation, which is 



\' ' *. . attended with some diffi- 



/ - i "" ' » i \ culty, was first effected by 



I '. K ' s * *. Czaplewski. On serum it 



. a ' ' • grows in the form of yellow- 



i # t i\ '* ' i 'J ish -grey, iiTegularly rounded 



,*>>' Si v J colonies about 1 mm. in 



x * » " f v i diameter, sometimes beconi- 



\ ■* ' t ' ' *• ' ' n S confluent to form, a com- 



\ */ fj *i$ '' ',' paratively thick layer. He 



\ | «X#/ V -, found that it also grew 



1 1 •*$ " on glycerin agar and in 



■^- .. ■ ..<*•'' bouillon. It is non-patho- 



"■ genie to various animals 



Fig. 83. — Smegma bacilli. Film preparation which have been tested, un- 



of smegma. less very large doses are 



Ziehl-Neelsen stain, x 1000. used. 



Cowie has found that acid- 

 fast bacilli are of common occurrence in the secretions of the external 

 genitals, mammse, etc., in certain of the lower animals, and that these 

 organisms vary in appearance. He considers that the term "smegma 

 bacillus " probably represents a number of allied species. 



The question may be asked — Do these results modify the 

 validity of the staining reaction of tubercle bacilli as a means of 

 diagnosis? The source of any acid-fast bacilli in question is 

 manifestly of importance, and it may be stated that when these 

 have been obtained from some source outside the body, or where 

 contamination from without has been possible, their recognition 

 as tubercle bacilli cannot be established by inicroscoiric examina- 

 tion alone. In the case of material coming from the interior of 

 the body, however, — sputum, etc., — the condition must be looked 

 on as different, and although an acid-fast bacillus (not tubercle) 



