THE ANTHRAX BACILLUS. 195 



becomes more and more indistinct until at last the 

 threads fall to pieces, the separate cells break up, and 

 the bright elliptical corpuscles, the spores, are set free. 



At first no further changes occur in the spores ; if 

 however a few are introduced with a needle into a 

 drop of bouillon or agar-agar upon a cover-glass, and 

 are then cultivated in an incubator, in a few hours 

 changes take place. At one or other pole of the 

 spore the very tender spore membrane breaks down, 

 thus allowing the budding rodlet to emerge. This rod- 

 let grows longer in the direction of the length 

 of the spore. At the same time the highly refractive 

 body, which at first completely filled the interior of 

 the spore membrane, becomes gradually smaller and 

 smaller, until finally, when the rodlet is full grown, 

 it has entirely disappeared. The empty membrane 

 generally remains, attached like a delicate veil to one 

 end of the rodlet, but at last it drops off and falls to 

 pieces. The young rodlet soon begins to divide, and 

 growth proceeds rapidly until all the nourishment is 

 exhausted, when spores again begin to be formed in 

 the thread. 



The observation of this germination of the spores 

 affords us an infallible means of distinguishing the 

 anthrax bacillus from the hay bacillus, with which 

 formerly it was frequently confused ; in the latter the 

 budding rodlet breaks through the side of the spore, 

 in the former it emerges from one or other pole. In 



