or other individuals. Barrow found them in the urine 

 from tuberculous kidneys in one case. 



Not only the clinical, but also the anatomical investi- 

 gation already reported, confirm Koch's statement that 

 tuberculous tissue, whether occurring in miliary nodules 

 or as cheesy masses, whether in lung, or liver, or spleen, 

 peritoneum, or meninges, contain tubercle bacilli, and 

 that no other tissue harbors them. Some, it is true, find 

 a larger proportion than did Koch, of individual rniliary 

 tubercles in which no bacilli can be detected ; this is 

 particularly true of Ziehl's examinations. Gibbes found 

 the bacilli in reticular tubercle in only one nodule out of 

 ten, in the non-reticular they were usually present. Koch 

 was inclined to the belief that his failure to detect them 

 was due to the fact that the organisms had lost their vi- 

 tality, and hence their power of absorbing aniline dyes ; 

 and demonstrated instances in which a very imperfect 

 staining of individual bacilli was visible. This explana- 

 tion is certainly plausible, yet it is possible that tubercu- 

 losis, like individual tubercles, may be produced by any 

 one of several causes. The clinical picture exhibits 

 many variations ; the histological structure is not peculiar 

 to tubercle. We have learned to distinguish trichinosis 

 from typhoid fever ; charbon symptomatique from char- 

 bon ; actinomycosis from pyaemia and pulmonary con- 

 sumption ; indeed, Pflug observed in the lungs of a cow 

 a miliary tuberculosis, and upon microscopic examination 

 was surprised to find that the individual tubercles con- 

 tained, not Koch's bacillus but the actinomyces bovis ; 

 this as yet solitary observation strengthens the suspicion 

 that among the numerous agents whose presence excites 

 the inflammation which results in tubercle formation, 

 there may be other parasites than the bacillus of Koch ; 

 that there may be several diseases etiologically distinct, 

 but anatomically so similar as to be included under the 

 common name tuberculosis ; the one characterized by 

 the famous bacillus, others, possibly, by organisms yet to 

 be discovered. In one instance, certainly, an analogy to 

 this supposition has become a demonstrated fact. For 



