XL] BACILLUS : PATHOGENIC FORMS. 105 



transitory swelling, and the animal so treated is afterwards pro- 

 tected against the fatal dose (Arloing, Cornevin, and Thomas). 

 The spores of the bacilli when heated up to 85 C. for six 

 hours lose their virulence (Arloing, Cornevin, and Thomas). 



(Z) Bacillus anthracis. Pollender, 1 Brauell, 2 Davaine, 3 and 

 then Bellinger 4 recognised in the blood of animals dead of 

 malignant anthrax the presence of stiff short and long rods, 

 which Davaine called bacteridie du charbon. They were 

 identified by Cohn 5 as bacilli in morphological respects similar 

 to bacillus subtilis, except that the bacilli anthracis are non- 

 motile. 



Koch 6 showed the ubiquitous distribution of these bacilli 

 in the blood of the organs, and especially of the spleen. He 



FIG. 73. HEART'S BLOOD OF A MOUSE DEAD OF AKTHRAX. 



1. Blood-discs. 



2. White blood-corpuscle. 



3. Bacilli anthracis. 

 Magnifying power 700. (Fresh specimen.) 



succeeded in cultivating these bacilli artificially, taking a bit 

 of spleen of a mouse (which animal is very susceptible to fatal 

 anthrax), and watching the growth of the bacilli in a micro- 

 scopic specimen. He saw that the rods multiply by division, 

 and that they grow into long, homogeneous-looking, straight 

 or twisted filaments in which after some time, and with free 

 access of air, bright oval spores make their appearance, while 

 the filaments become homogeneous and swollen. These spores 

 become free, and when artificially cultivated or injected into 

 a rodent animal, germinate into the characteristic bacilli ; 



1 Viertelj. f. gericht Med. 1855. 2 Virchow's Archiv, vol. 14, 1858. 



3 Comptes Rrndus, Ivii. 1663. * Med. Centralblatt, June, 1&72, 



Rellr. z. Bwl. d. Pfianzen, vol. ii. 6 2bid. vol. iii. 



