OUTLINES OF BACTERIOLOGY 



families, viz. Vibriona, the bacteria are collected together into five 

 genera : 



(1) Bacterium. Cylindrical cells (Fig. la). 



(2) Vibrio. Curved cells (Fig. 16). 



(3) Spirochaete."! „ , , , i, .ti- i \ 



, ' „ V Corkscrew shaped cells (Jig. Ic). 



(5) Spirodiscus. a variety of spirillum not since observed. 



From this time onward the study of bacteria became a science in 

 itself As soon as Koch's work on Bacillus anthracis (1876), showed 



Fig. 1. 



definitely the connection between bacteria and disease, and when, in 

 the realm of technical industries, the important r61e of these small 

 organisms was discovered, universal interest was awakened in them, 

 and the results of investigators were eagerly awaited. At the present 

 day this young science has developed to such an extent, that it has 

 already many branches. The sum total of the gain to humanity 

 obtained through the study of these minute forms, is considerable, 

 and there are very few branches of other sciences in which a slight 

 knowledge of the fundamental principles of Bacteriology is not useful. 



