IX.] 



BACILLUS. 



101 



other elementary cubical, spherical, or rod-like mass of pro 

 toplasm there appears a bright dot; this enlarges at the 

 expense of the protoplasm until in its fully developed state 

 it has an oval shape. The whole of the protoplasm of an 



FIG. 41. THE SAME BACILLUS AS IN PRECEDING FIGURE. 

 At i, spores have made their appearance. 



element is not consumed in this process, a small trace always 

 remaining unused at one or both ends. The sheath enlarges 

 and the bacillus looks much thickened ; then the sheath 

 breaks, and the spore with the remnant of protoplasm 



/ 



/v 



FIG. 42. THE SAME BACILLUS AS IN 

 PRECEDING FIGURE. 



Some of the spores are germinating 

 into bacilli. 



FIG. 43. BACILLUS SUBTILIS OF HAY 

 INFUSION. 



At 



i, spores are 



are germi 



nating into 



becomes free. Soon this remnant disappears, if it had not 

 disappeared while the spore was still contained within the 

 sheath, and now the spore is free. Under the most 

 favourable conditions a spore may be formed in each 



