CHAPTER II. 

 FUNGI 



BACTERIA 



Habitat. Bacteria occur in the air, the soil, fresh and salt 

 water, hot springs and the icy waters of the arctic regions; 

 they are found upon lifeless animal and vegetable substances. 

 In fact, bacteria seem to be everywhere. 











f ~ B 



/ 



FIG. 7. Varieties of spherical forms: a, tendency to lancet-shape; b, 

 tendency to coffee-bean shape; c, in packets; d, in tetrads; e, in chains; /, in 

 irregular masses. X 1000 diameters. (After Fliigge.) 



Morphology. Colonies of bacteria are extremely variable 

 in form and color. Each class of bacteria forms characteristic 

 colonies. 



Histology. Bacteria are the simplest, smallest plants 

 known. They are unicellular and vary in size from 5~oTFo 

 to roll on of an inch. In a few of the forms the outer wall 

 is composed of cellulose. In most of the others the wall is 



