8 CONTENTS. 



Spores. Vegetating- and reproductive forms. Endos- 



pore, arthrospore. Sporulation. Position of the spore; 



median, terminal, intermediate. Resultant cell forms; clos- 



tridium, "drum-sticks." Cause of spore formation. Aspor- 



ogenic bacteria. Germination. Spore structure. Re- 

 sistance of spores. Spontaneous generation. 



CHAPTER IV. 



The Environment of Bacteria . . . . .58 



Conditions of .growth Necessity of moisture. Chem- 

 ical composition of the cell. Sources of carbon, nitrogen, 



hydrogen, oxygen, and other elements. Reaction of the 



medium. Distribution of bacteria in nature, where absent. 



Classification according to habitat. Saprophytic and 



parasitic bacteria. Obligative and facultative forms. 



Classification according to oxygen requirements. Aerobic 



and anaerobic bacteria. Obligative and facultative forms. 



Microbic association. 



Temperature, minimum, maximum and optimum. Ther- 



mophilic bacteria. Effect of cold and heat on vitality. 



Action of light, high pressure, electricity, Chemotaxis. 



CHAPTER V. 



The Chemistry of Bacteria 79 



The number and kind of products vary with each species. 

 Influence of environment. Accumulation of waste-pro- 

 ducts. Synthetic and analytic, primary and secondary pro- 

 ducts. 



Bacterial proteins, tox-albumins. Venoms, plant albu- 

 moses as abrin and ricin. Toxins; synthetic products, elabor- 

 ated within the cell, not bases or proteins. -Ferments, 



organized and unorganized. Enzymes, their classification. 



Ptomai'ns. Alkalis. Acids. Alcohols. Gases. 



Classification of bacteria according to function. 



Fermentations. Their cause, the nature of the chemical 



changes induced. Diverse fermentations, alcoholic; acetic 



acid, vinegar, summer complaint; lactic acid, dental caries, 

 stomach and intestinal disorders, souring of milk, koumiss, 

 cheese; butyric acid, sauerkraut, ensilage, cheese, retting; 



viscous or slimy fermentations. Fermentations of fats, flavor 



of butter. Hydrogen sulphide and ammoniacal fermentations 



of urine. Nitrification in water and soil, saltpeter. Deni- 



trification. Indigo reduction. Putrefaction, bacteria as 



scavengers perpetuate life. 



