148 MICRO-ORGANISMS AND DISEASE. [CHAP. 



a large area. The cedematous fluid is clear and contains 

 only a few bacilli. 



Archangelski ( Centralblatt /. d. med. Wits. 1883, p. 257) claims to 

 have ascertained that if an animal be inoculated with anthrax, many 

 hours before the bacilli appear in the blood, there are present numbers 

 of spores. Just before death they all become changed into the bacilli. 

 He further maintains that those spores taken from the blood can be 

 shown to multiply by division, and without changing into bacilli, by 

 cultivating them artificially with exclusion of oxygen. I have shown, 

 however (Reports of the Medical Officer of the Local Government Board 

 for 1883), that none of these assertions are borne out by actual observa- 

 tion, and that they are erroneous. 



FIG. 80. FROM A PREPARATION OF HEART'S BLOOD OF A GUINEA-PIG DEAD 

 OF ANTHRAX. 



1. Red blood-disc--. 



2. White corpuscle. 



3. Bacilli anthracis. 



Magnifyirg power 700. (Stained with Spiller's purple.) 



Any fluid containing proteid material is a suitable nutrient 

 medium for the bacilli ; they grow abundantly at all tem- 

 peratures between 15 and 43 C, best between 25 and 

 40 C. They elongate and divide rapidly, and the bacilli 

 grow out into long curved and peculiarly twisted filaments 

 which often form bundles, the individual filaments being 

 twisted round one another like the strands of a cable. 



The bacillus anthracis grows best in neutral fluids, and to 



