GENERAL MORPHOLOGY AND 



excretions, and with blood which issues from the 

 mouth and nostrils before death. 



When spores are introduced into a suitable 

 medium at a favourable temperature, they develop 

 again into rods. The spore loses its sharp con- 

 tour, and, at one pole or on one side, a pale process 

 bursts through the membrane, gradually growing 

 into a rod from which the empty capsule is 

 thrown off (Figs. 52 and 53). 



Spores differ from the parent cells in their be- 



. ... 







FIG. 57. SPORE-BEARING THREADS 

 OF BACILLUS ANTHRACIS, 

 DOUBLE-STAINED WITH FUCH- 

 SINE AND METHYLENE BLUE, 

 X 1200. 



FIG. 56. SPORES OF BACILLUS AN- 

 THRACIS, STAINED WITH GENTIAN 

 VIOLET, AFTER PASSING THE 

 COVER-GLASS TWELVE TIMES 

 THROUGH THE FLAME, X I2OO. 



haviour to staining reagents. Like them, they can 

 be stained with aniline dyes, but not by the 

 ordinary processes. They require to be specially 

 treated. This is probably due to the tough capsule, 

 which must first be altered or softened by heat or 

 strong acid, until it allows the stain to penetrate. 



Once stained, they again differ from the parent 

 cells in resisting decolorisation ; this fact is taken 

 advantage of to double-stain spore- bearing bacilli. 

 . In staining micro-organisms, the protoplasm is 



