EELATION OF PATHOGENIC TO SEPTIC BACTEEIA. 35 



sistance of the solid material, but in the same manner as is the 

 case in the pure pork broth. Like a beautiful bed of more or 

 less distinctly dendritically branched weeds the masses of 

 bacillus threads springing up at the bottom of the vessel rise 

 into the superimposed layers. The appearance produced 

 hereby is very fine after the growth has made some progress; 

 we perceive the growth to rise perpendicularly from a common 

 bed at the bottom of the vessel like a forest of dendritically 

 branched plants. The gelatine of the deepest layer becomes 

 of course here first liquid. This growth does not yield spores 

 at any time owing to being far away from the surface, and it 

 always remains in the state of masses and convolutions of 

 bacillus threads. 



The following confirms in a marked manner what has just 

 been said about the spore formation. In a flask filled to a 

 third or fourth of its volume with solid gelatine pork, Bacillus 

 anthracis is introduced on to the middle of the surface, as in 

 the case above described. Masses of bacilli soon spread over 

 the surface ; the superficial layer of the gelatine becomes 

 liquefied by the growth, and this liquid layer teems with 

 spores. Now, I decant this liquid layer, and having plugged 

 the flask again, subject it to boiling. What will happen ? 

 By the process of decanting a quantity of the growth is 

 removed, but a great deal (spores and threads) is still left 

 behind on the surface ready for fresh growth. Next, heating 

 the gelatine mass, and thereby making it liquid, of course all 

 growth (spores and threads) sinks to the bottom of the flask. 

 But boiling the mass for about a minute or so does not kill all 

 living matter. The threads of bacillus are indeed necessarily 

 killed by the boiling, but not the spores. This is proved by 

 the fact that on allowing the gelatine to cool again it becomes 

 solid, and now all particulate matter is kept enclosed at the 

 bottom of the flask ; and a new and beautiful growth of typical 

 Bacillus anthracis growing from the spores soon makes its 

 appearance at the bottom of the flask, while the surface of 

 course remains free. One of the finest growths of Bacillus 

 anthracis threads in the shape of a forest-like mass of per- 



