[SHANLY] HEAT RESISTANCE OF BACTERIAL SPORES 133 



Species different strains vary in their maximal heat resistance. It is 

 very obvious therefore that one of the questions proposed in our in- 

 troductory paragraphs must be answered in the negative: the heat 

 resistance of the endospores of any given spore-bearing bacterial species 

 cannot safely be employed as a means of species differentiation. 



ON THE HEAT RESISTANCE AND THE SIGNIFICANCE OF THE GRANULES 

 IN TUBERCLE AND ALLIED BACILLI. 



I now come to the second part of this investigation, namely to 

 the study of the relationship of the bodies seen in tubercle bacilli to 

 endospores proper, as determined by their heat lesistance. For the 

 purpose of this research I am greatly indebted to Dr. W. B. Wherry 

 cf Cincinnati for providing me with the culture ot a strain of B. 

 tuberculosis, which exhibits the spore-like bodies to an extent rarely 

 observed. The culture in question was brought to America from 

 Koch's laboratoiy in Berlin by Prof. V. C. Vaughan of Ann Arbor in 

 1888, and has been cultivated outside the body ever since, until now 

 it has attained an extreme degree ot saphrophytism, growing easily on 

 the ordinary media of the laboratory, and forming colonies which are 

 visible in the course of three days. Dr. Wheiry has described and 

 figured this organism,^ and we can wholly confirm his general descrip- 

 tion. 



Nocard and Roux^ observed the spore-like bodies in old cultures 

 of the tubercle bacillus particularly when strained by Ehrlich's method. 

 Metchnikoff' has described them in tubercular sputum, as also in the 

 anterior chamber of the eye of a rabbit dead of tuberculosis. Klein* 

 found them in glycerine-agar and broth cultures, and they have been 

 described and pictured by Coppen Jones.^ These spore-like bodies 

 are found frequently in preparations from old pulmonary cavities 

 as rounded bodies of greater diameter than the tubercle bacilli ; from 

 one to three or more may occur in a single rod. They take up the 

 dye strongly, and still retain it when the rest of the bacillary body 

 is decolorized by nitric acid. These bodies form abundantly in this 

 strain obtained from Dr. Wherry, and we have found that with age 

 they become Gram positive. I herewith reproduce a figure of these 

 bodies afforded by Dr. Wherry (Plate II) drawn after vital staining 



iCtbl. f. Bakt. Erste Abt. Originale 70, 1913, p. 115. 

 See also Jour. Infect. Dis. XIII: 1913, p. 144. 



2 Ann. de Pasteur, I, 1887, p. 19. 



3 Virchow's Arch., Vol. 113, 1888, p. 63. 

 * Ctbl. f. Bakt., Bd. 7, 1890, p. 793. 



' Ctbl. f. Bakt., Abt. I, Vol. XVII, 1895, p. 1. 



Sec. IV, 1915—9 



