SHAPES OF BACTERIA. 



193 



structure can be made out in them by the beginner, to whom 

 they usually appear at first sight like pale, translucent or watery 

 bits of protoplasm. Investigation has shown, however, that they 

 possess a cell-wall (probably composed of cellulose) and a non- 

 homogeneous protoplasm. Unlike Protococcus^ but like yeast- 

 cells, the cells of bacteria contain no chlorophyll. Kuclear mat- 



FIG. 98. Bacillus Megateriurru 

 Rods (unstained) in various 

 aggregations as commonly seen 

 with a high powor after their 

 cultivation in bouillon and 

 while rapidly growing and mul- 

 tiplying by transverse divi- 

 sion. 



FIG. 99. Bacilli from 

 Hay Infusion (unstain- 

 ed). The filaments at 

 the left in a condition 

 of active vegetation. 

 The middle filament 

 forming spores. The 

 filament to the right 

 contains five spores 

 enclosed in otherwise 

 empty cells, the walls 

 of which bulge, proba- 

 bly from the absorp- 

 tion of water. 



ter is present, either scattered about, or, if the views of Biitschli 

 be accepted, composing most of the protoplasmic body itself. 

 Many bacteria bear appendages in the shape of flagella or 

 cilia ; but these can only be demonstrated in special cases, and 

 by special methods. They are believed to be locomotor organs, 

 and in some cases have been seen in active motion (Fig. 103). 



