MYCOBACTEMIUM TUBERCULOSIS. 411 



und Biologie des Tuberkuloseerregers, Vienna, 1893; Coppen Jones 

 (C. B. XVII, 1); Hayo Bruns (C. B. xvil, 817); Cornet, Die Tuber- 

 kulose, 1899. 



Microscopic Appearance. — In sputum and cultures 

 usually unbranclied, slender rods, 1.5-4 p. long, only 

 0.4 /i thick, which often are slightly bent (61, vii, ix, x). 



More recently many writers have observed thread and 

 true branched forms — in sputum and in cultures, and in 

 the latter, with careful preparation, they are predominant 

 — which are injured and broken apart by only the rough- 

 est preparation. (Literature, history, and good illustra- 

 tions by Coppen Jones, I. c.) Lubinski obtained long 

 threads without branching upon acid potatoes (C. B. 

 XVIII, 125). 



Inside of the tubercle bacillus from sputum and pure 

 culture there are sometimes found unstained vacuoles, 

 sometimes peculiar structures which give an especially in- 

 tense, dark red color with carbol-fuchsin. Still, these 

 latter bodies do not present the regular form of the true 

 spores of bacilli; also statements regarding resistance and 

 germination are not at hand. Coppen Jones compares 

 them to the chlamydospores of the mucorini. 



In the same article the same author described very 

 remarkable forms from tubercular sputum resembling the 

 clubs of actinomyces, but which he recognized not as or- 

 ganized forms directly formed by the T. B. , but (like acti- 

 nomyces-clubs) as secretions, concrements, etc. 



Friedrich found T. B. resembling actinomyces — i. e., 

 clubbed, dense, radiating formations — in sections of or- 

 gans from animals which succumbed to a rapid tubercu- 

 losis infection (see p. 416). 



Motility. — According to all authors motility is lacking. 

 Schumowski claims to have constantly seen a slow motion 

 of theT. B. (C. B. xxiii, 838.) 



Staining Properties. — The T. B. stains so difficultly 

 and imperfectly wdth the ordinary aqueous solutions of 

 anilin dyes that these are never employed. Also the stain 

 suggested by Koch, accomplished by prolonged action of 

 alkaline methylene-blue, has only a historical interest. 



To-day two methods (Tech. Appendix), with innumera- 

 ble (insignificant) modifications, are almost exclusively 



