736 Tuberculosis 



subsequently able to start cultures of the smegma baciUus upon glycerin agar- 

 agar. Human blood-serum is thus found to be the best medium upon which to 

 start the culture. 



Agar. — A culture thus isolated grew upon all the usual culture-media._ Upon 

 glycerin-agar, at 37°C., the colonies appeared as minute, dull, grayish-white, dry, 

 rounded scales, which later became lobulated and velvety. At room tempera- 

 ture the dry appearance of the growth was retained. The water of condensation 

 remained clear. 



Potato. — On potato the growth was luxuriant, grayish, and duU. 



Milk. — Milk is said to be an exceptionally good medium, growth taking place 

 in it with rapidity and without coagulation. 



Bouillon. — The growth forms a dry white scum upon the surface, the medium 

 remaining clear. 



Pathogenesis. — So far as is known, the smegma bacillus is a harmless sapro- 

 phyte. 



Moeller's Grass Bacillus 



Bacillus Phlei 



Bacilli found in milk, butter, timothy hay, cow-dung, etc., which stain like the 

 tubercle baciUus and may be mistaken for it, have been described by Moeller.* 

 The organisms so closely resemble the tubercle baciUus that guinea-pig inocu- 

 lations must be resorted to in cases of doubt, but as some of these organisms 

 sometimes kill the guinea-pigs after a month or two, and as smaU nodules or 

 tubercles may be present in titie mesentery, peritoneum, liver, lung, etc., of such 

 animals, the diagnosis may have to be subjected to the further confirmation of a 

 histologic examination of the lesions in order to exclude tuberculosis. In cases of 

 this kind it should not be forgotten that the tubercle baciUus can be present in the 

 substances mentioned, so that the exact differentiation becomes a very fine one. 

 An instructive study of these organisms has been made by Abbott and Gilder- 

 sleeve,! who, in an elaborate work upon the "Etiological Significance of the 

 Acid-resisting Group of Bacteria, and the Evidence in Favor of Their Botanical 

 Relation to BaciUus Tuberculosis" a work that gives complete references to the 

 literature of the subject, come to the foUowing conclusions: 



1. That the majority of the acid-resisting bacteria may be distinguished from 

 true tubercle bacilli by their inabiUty to resist decolorization by a 30 per cent, 

 solution of nitric acid in water. 



2. That some of the acid-resisting bacteria are capable of causing in rabbits and 

 guinea-pigs nodular lesions suggestive of tubercles; that these lesions, whUe often 

 very much like tubercles in their histologic structure, may nevertheless usually be 

 distinguished from them by the foUowing pecuUarities: 



(o) When occurring as a result of intravehous inoculation, they are always 

 seen in the kidneys, only occasionaUy in the lungs, and practicaUy not at aU in 

 the other organs. 



(6) 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 pro- 

 gressive caseation, as is the case with true tubercles. 



(d) They are more commonly and conspicuously marked by the actinomyces 

 t3T)e 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 occasionaUy seen in tubercles. 



3. That by subcutaneous, intravenous, and intrapulmonary 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 occasionaUy present in dairy products, they are to be regarded 

 as of no significance, etiologicaUy speaking, but may be considered as accidental 

 contaminations from the surroundings, and not as evidence of disease in the 

 animals. 



♦"Deutsche med Zeitung," 1898, p. 135; "Deutsche med. Wochenschrift," 

 1898, p. 376, etc. 

 t/'Univ. of Penna. BuUetin," June, 1902. 



