CHAPTER XIII. 



SPIROBACTERIUM (Spirillum}. 



SPIRILLA are filaments of a spiral shape, motile, and owing 

 to their shape follow a spiral course when moving. They 

 are probably capable of forming minute bright spores, 



1. Septic spirilla. These are found in all kinds of putrefying 

 organic substances, and are of three kinds. 



FIG. 94. SPIRILLUM TENUE, (1) SINGLY AND (2) IN SWARMS (AFTER COHN). 



(a) Spirillum tenue. This is much finer and more wavy 

 than vibrio serpens, the turns being closer together and spiral. 

 Its length varies between 0'002 and 0'005 mm. ; it often forms 

 continuous felted masses ; it is motile. 



Occasionally the spirilla grow to a great length two, three, 

 and more of them forming a chain ; the individual spirilla are 

 not arranged in a linear series, but folded into a zigzag. This 

 form, which in reality is not a special kind of spirillum, is 



K 2 



