424 BACTERIA PATHOGENIC TO MAN 



principal, factor in producing disease. These cases were all fatal, and 

 only once was the character of the disease recognized during life. As 

 the clinical symptoms and the lesions in the human subject as well as in 

 the animals experimentally inoculated with the streptothrix often resem- 

 ble those of miliary tuberculosis, so that a number of these cases have 

 been reported as pseudotuberculosis, the question is naturally suggested 

 whether such cases of streptothrix tuberculosis are not more numerous 

 than the few reported cases would indicate. The almost universal 

 prevalence of genuine tuberculosis and the extreme gravity of the dis- 

 ease have so long occupied the attention and study of the medical pro- 

 fession that much is taken for granted, and cases in which the symp- 

 toms and lesions resemble with some closeness those characteristic of 

 the well-known disease may easily be set down without question to 

 the account of the tubercle bacillus. The cases of streptothrix tuber- 

 culosis so far reported have all been fatal, and the lesions for the most 

 part have been widely distributed, but in a number of cases old lesions 

 have been found which suggest that the disease may have been localized 

 for a longer or shorter time, and then, by some accident, may have 

 become rapidly general. In this respect, also, these cases may resemble 

 tuberculosis. Whether all cases of streptothrix disease in the human 

 subject are general and fatal, or, as in tuberculosis and actinomycosis, 

 there may be cases of localized disease which recover, are questions 

 which have not been decided at the present time. The methods em- 

 ployed to demonstrate the presence of tubercle bacilli render the strepto- 

 thrices invisible. Again, unless the observer keeps in mind the possi- 

 bility of streptothrix infection, he may not appreciate the importance 

 of the slender threads with or without branches, and may consider 

 them accidental bacilli, or varieties of leptothrix or non-pathogenic 

 fungi. As the lungs have appeared to be the seat of the primary 

 infection in most of the cases of human streptothrix disease, it is very 

 desirable that all cases presenting the physical signs of tuberculosis, 

 in which repeated examinations fail to discover the tubercle bacillus, 

 should be systematically examined for streptothrix threads. In this 

 way alone can the frequency of the disease be determined. Gram's 

 method of staining or the Ziehl-Neelson solution decolorized with 

 aniline oil seem to be the most reliable agents for demonstrating these 

 organisms. The streptothrices are widely distributed and are not very 

 infrequently met with, but as yet, with the exceptions mentioned above, 

 very little is known about them. Kruse mentions nineteen varieties, 

 including the actinomyces. Some of them are non-pathogenic; some 

 are pathogenic for certain animals, and others are pathogenic for both 

 man and animals. 



In studying the descriptions of the different varieties of these micro- 

 organisms, it seems that, as in the case of certain bacteria, different 

 observers may possibly have described the same variety under different 

 names. 



Ttittle's report of the case of general streptothrix infection at the 

 Presbyterian Hospital, gives such a good clinical, bacteriological, and 



