350 Tuberculosis 



(b) They constitute a localized lesion, having no tendency 

 to dissemination, metastasis, or progressive destruction of 

 tissue by caseation. 



(c) They tend to terminate in suppuration or organization 

 rather than in progressive caseation, as is the case with true 

 tubercles. 



(d) They are more commonly and conspicuously marked 

 by the actinomyces type of development of the organisms 

 than is the case with true tubercles, and these actinomycetes 

 are less resistant to decolorization by strong acid solutions 

 than are those occasionally seen in tubercles. 



3. That by subcutaneous, intravenous, and intrapulmon- 

 ary inoculation of hogs (4) and calves (15) the typical 

 members of the acid-resisting group are incapable of causing 

 lesions in any way suggestive of those resulting from similar 

 inoculations of the same animals with true tubercle bacilli. 



4. That though occasionally present in dairy products, 

 they are to be regarded as of no significance, etiologically 

 speaking, but may be considered as accidental contamina- 

 tions from the surroundings, and not as evidence of disease 

 in the animals. 



5. That the designation "bacillus" as applied to this 

 group of bacteria and to the exciter of tuberculosis is a 

 misnomer; they are more correctly classified as actino- 

 myces. 



Isolation and cultivation of these organisms is easy, and 

 more than any other measure serves to differentiate them 

 from the tubercle bacillus, as they grow upon nearly all the 

 culture media with rapidity and luxuriance. 



PSEUDO-TUBERCULOSIS. 



BACILLUS PSKUDO-TUBERCULOSIS. 



Pfeiffer,* Malassez and Vignal,t Eberth,J Chantemesse, 

 Charrin, and Roger || have all reported cases of so-called 

 pseudo-tuberculosis occurring in guinea-pigs, and character- 

 ized by the formation of cellular nodules in the liver and 

 kidneys much resembling miliary tubercles. Cultures made 

 from them showed the presence of a small motile bacillus 



* " Bacillare tuberculose, u. s. w.," Leipzig, 1889. 



t " Archiv de Physiol. norm, et Path.," 1883 and 1884. 



t " Virchow's Archiv," Bd. en. 



"Ann. de 1'Inst. Pasteur," 1887. 



|| " Compte-rendu de 1'Acad. des. Sci.," Paris, t. cvi. 



