SECTION 1. 

 GENERAL BACTERIOLOGY. 



CHAPTER I. 

 STRUCTURE, GROWTH AND DISTRIBUTION. 



Nature of the bacteria. The bacteria belong to the 

 group of plants known as fungi. The fungus plants do 

 not contain the green coloring matter found in ordinary 

 plants. They live on dead or living animal or vegetable 

 matter. Many of the fungi are well known to the 

 farmer and are of great economic importance causing, 

 as they do, such plant diseases as the rusts, smuts and 

 mildews. Other examples of fungi are the various 

 kinds of molds, toadstools and mushrooms. These are 

 more familiar as they are large enough to be seen by the 

 unaided eye, while many other kinds of fungi and es- 

 pecially the bacteria are unfamiliar objects because by 

 the unaided eye an individual plant can not be seen. 

 When massed together in large numbers they become 

 visible but such groupings are rarely found in nature. 



While the bacteria, themselves, are not familiar ob- 

 jects the effect they produce is very evident in the sour- 

 ing of milk, the spoiling of meat and eggs, the produc- 

 tion of diseases in plants and animals, and in many 

 other ways which are not so readily recognized. 



Knowledge relating to the bacteria has nearly all 

 been gained within the last thirty years although the 

 bacteria were first seen by a Dutch lens-maker, Antoni 

 van Leeuwenhoek, in 1675. For nearly two hundred 

 years after they were first discovered but little of im- 

 portance was learned concerning them. 



