1897J MICROSCOPICAL JOURNAL. 187 



Indeed, the color of our mischievous microbe played a 

 conspicuous part in many of those natural phenomena 

 which, by their lack of apparent cause, were in early 

 times relegated to the domain of the su[)ertiatural. That 

 wavering, cold, uncanny phosphorescent light, seen at 

 night time in putrid plants or by the sea side, is our in- 

 nocuous microbe. The consecrated wafer placed in the 

 bacteria-laden air of the church edifice over night was 

 found besprinkled with crimson drops in the morning. 



The legends are long and tragic of the dire calamities, 

 unmentionable crimes and swift retributions which the 

 strange appearance of our chromogenic microbe was 

 supposed to foreshadow. 



A recourse to the supernatural to elucidate all these 

 natural phenomena, is no longer necessary, for to-day, 

 we cultivate and study the tiny bacillus prodigiosus 

 which made the drops of blood, the mingled green and 

 blue phosphorescence. 



3. Heat and Oxygen. — Like the larger plants, differ- 

 ent species of bacteria require different temperatures for 

 their growth. Most all grow well at 60° to 80° F., hut 

 the tubercle bacillus ceases to grow below 92° F. 



As microbes assume very diverse forms in accordance 

 with the nature of their environments, so also their 

 habitat and mode of life divide them into very distinct 

 classes. 



The aerobines can subsist only when they bri'ath the 

 natural oxygen they withdraw from the atmospheie. 



The anaerobines live within lliiids and liviug organ- 

 isms and derive the oxygen necessary for their respira- 

 tion from the oxygenated substances in which they are 

 found. To the latter class, belong all microbes which 

 provoke pathological changes when iuti-odui:ed into the 

 blood. 



4. Pathofjenefiis. — Living animal tissues afford unfa- 

 vorable soil for bacterial growth. When introduced 



