CONTENTS. 



CHAPTER I. 



Pag-e. 

 Form and Classification of Bacteria .... 15 



Definition of bacteria. Microscopic plants and animals, 



distinction.— —Bacteria as plants. — -Bacteria, fission fungi or 

 schizomycetes; moulds, thread fungi or hyphomycetes; yeasts, 

 budding fungi or blastomycetes. Absence of a natural classi- 

 fication. Bacteria classified according to form; micrococcus, 



bacillus, spirillum. Modifications; bacterium, vibrio, spiro- 



chaete. Division into species. Influence of environment on 



form and size. Involution forms. Viriations due to meth- 

 ods of examination. Plasmolytic changes. Pleomorphism. 



Constancy of species. Attenuation. Origin of new spe- 

 cies. 



CHAPTER II. 



Size and Structure of the Bacterial Cell 24 



Bacteria as unicellular organisms. Called the smallest 



of living beings. Existence of still more minute life. 



Micromillimeter or micron. Size of bacteria. 



The cell-wall, composition, demonstration. Plasmolysis. 



Softening of the outer layer, the capsule. Zooglea. 



The contents of the cell, composition. Existence of a 



nucleus. Appearance of contents; granulations, polar bodies, 



color, absence of chlorophyll. Granulose reaction. 



Motility. Molecular or Brownian movement. Real 



motion, fiageUa or whips. Number and arrangement. 



Giant whips. 



CHAPTER III. 



The Life-history of Bacteria .... 41 



Rapidity of multiplication. Cell division: diplo-bacillus, 



threads; diplococcus, streptococcus, tetrad, sarcine, staphylo- 

 coccus; vibrio, spirillum. 



