CHAPTER I. 



THE MORPHOLOGY OF BACTERIA. 



A. MORPHOLOGY NORMAL FORMS: 



Coccus, BACILLUS, SPIRILLUM. 



B. MORPHOLOGY ATYPICAL AND AB- 



NORMAL FORMS. 



1. Variation. 



2. Degeneration and Involution. 



3. Pleiomorphism. 



4. Branching. 



C. SIZE OF BACTERIA: WEIGHT OF 



BACTERIA. 



D. STRUCTURE AND CONSTITUENTS OF 



THE BACTERIAL CELL. 

 1. Cell Membrane, Ectoplasm, 

 Capsule, Zooglea. 



2. Cell Substance, Cytoplasm, 

 Nucleus, Metachromatic and 

 Polar Granules, Flagella, 

 Spores, Germination of Spores, 

 Arthrospores. 



E. REPRODUCTION AND CELL DIVISION 



IN BACTERIA. 



F. CELL GROUPING. 



G. CLASSIFICATION OF BACTERIA. 



1. Relation of Bacteria to Higher 



Plants. 



2. Classification. 



H. MUTATION. CONSTANCY OF TYPES. 



A. NORMAL FORMS: COCCI, BACILLI, SPIRILLA. 



THE normal forms of the true bacteria are very simple, and are 

 included in three fundamental types: the sphere (coccus, plural cocci), 

 the straight rod (bacillus, plural bacilli), and the curved rod (spirillum, 

 plural spirilla) . There is in addition a group of organisms intermediate 

 between the true bacteria and the molds, which is characterized by 

 a filamentous type of growth. The members comprising this group 

 of filamentous organisms are commonly known as the higher bacteria 

 or Chlamydobacteriacese. An organism belonging to one of these 

 groups always reproduces its kind under normal conditions; that is, 

 a coccus always reproduces a coccus, a bacillus always reproduces a 

 bacillus, and a spirillum always reproduces a spirillum. 



Cocci. A single coccus is typically spherical, although those 

 organisms in which division is taking place may be temporarily some- 

 what elongated in one diameter, thus appearing oval in outline at this 

 stage of their development. They may even resemble very short 

 bacilli in extreme instances. The habitual occurrence of cocci in pairs, 

 frequently with their proximate surfaces flattened, is a noteworthy 

 morphological characteristic of certain members of this group. They 

 are referred to as diplococci. The flattening of the proximated sur- 

 faces may be associated with an elongation of the axes of the organisms 

 parallel to the plane of apposition, which leads to "coffee bean" 



