CLASSIFICATION 9 



certain specific substances (ferment) found in the blood of immu- 

 nized animals, called bacteriolysins and agglutininsfi Where 

 great masses of bacteria are clumped in excessive mucilaginous 

 material we speak of this condition as zooglea. (Fig. 7.) 



We sometimes find, as a prolongation of the cell wall, filamentous 

 organs of locomotion known as flagella. Not all bacteria possess 



FIG. 7. Zooglia formation. (Leuconostoc.) (Kolle and Wassermann.) 



these^ut those that do, are called trichobacteria. Those that have 

 notpageiiaVre called gymnobacteria. Trichobacteria are classified 

 accw4wrg"1x) the number and location of the flagella. When they 

 have one flagellum we call them monotrichous bacteria, and amphi- 

 trichous when there are two flagella, one at each pole. (Fig. 8.) 

 When the cell is surrounded by flagella, it is known as a peritrichous 

 bacterium, and lophotrichous when the flagella are arranged in tufts 

 of two or more. These are simple adjectives and not now used 

 as terms of classification. The tetanus bacillus is an example of a 

 peritrichous organism, while the bacillus of green pus is called 

 monotrichous, because of its single flagellum. (Fig. 9.) 

 t Flagella are not pseudopods, but distinct organs of locomotion. 

 In certain bacteria of the Beggiatoa, locomotion is accomplished 



