210 PATHOGENIC BACTERIA. 



dences pro and con point more strongly in the negative 

 than in the positive direction. 



The fragments do not look like the spores of any other 

 organisms. When spores occur in the continuity of 



FIG. 60. Tubercle bacillus in sputum (Frankel and Pfeiffer). 



bacilli, they are generally discrete oval refracting bodies 

 easily recognized. The fragments seen in the tubercle 

 bacillus are irregular and biconcave instead of oval, have 



FlG. 6l. Tubercle bacilli: I, forms suggesting sporulation; 2, forms de- 

 scribed as leaded ; the open spaces in the fragmented rods are sometimes mis- 

 taken for spores. 



ragged surfaces, and are without the refraction peculiar 

 to the ordinary spore. 



The spaces between the bacillary fragments cannot be 

 made to stain like the spores of other species. Finally, 



