PART FOURTH. 



SAPROPHYTES. 



I. BACTERIA IN THE AIR. II. BACTERIA IN WATER. III. BACTERIA IN 

 THE SOIL. IV. BACTERIA ON THE SURFACE OF THE BODY AND OF EX- 

 POSED Mucous MEMBRANES. V. BACTERIA OF THE STOMACH AND 

 INTESTINE. VI. BACTERIA OF CADAVERS AND OF PUTREFYING 

 MATERIAL FROM VARIOUS SOURCES. VII. BACTEBIA 

 itf ARTICLES or FOOD. 



