BACILLUS SMEOMATtS. 349 



ism is not regularly associated with syphilis and has 

 nothing to do with its causation. 



Bacillus Smegmatis. — In 1885 Alvarez and Tavel 

 discovered in the fatty secretions about the genitalia an 

 organism that suggested both the bacillus of syphilis 

 and that of tuberculosis. It was found both in syphi- 

 litic and in healthy persons. Their observation has 

 been abundantly confirmed by others, and the organism 

 to which they directed attention is now regarded as 

 pretty commonly present in the smegma. It is I'jnown, 

 therefore, as the smegma bacillus (bacillus smegmatis). 

 In this secretion it is found in clumps located upon or 

 within epithelial cells. It stains by the method used in 

 staining bacillus tuberculosis. It has no pathogenic 

 power. It is said to have been artificially cultivated 

 upon coagulated hydrocele fluid and in milk. 



It is not unlikely that bacillus smegmatis and bacillus 

 syphilidis are very closely allied, if not identical. 



In addition to the species mentioned, quite a group 

 of other " acid-proof" bacilli, as they are called, have 

 been described by different investigators. They are 

 characterized by staining as does the bacillus tubercu- 

 losis, by retaining the stain to greater or less extent 

 when treated with acids and alcohol, and by being in 

 many instances strikingly like bacillus tuberculosis in 

 their moi-phology. The members of this group seem to 

 be distributed pretty widely in nature. They have been 

 detected in non-tuberculous sputum, in gangrene of the 

 lung, in the normal intestinal contents of man and 

 domestic animals, in the soil, in fodder — i. e., grass, 

 hay, and seed— in manure, and in butter. They are 

 not regularly found under any of these conditions, and 

 they are rarely present in very large numbers. Inas- 



