PART FOURTH. 
SAPROPHYTES. 
I. Bacteria IN THE AIR. II. BacTERIA IN Water. III. Bacteria IN 
THE Sort. 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. Bacteria 
IN ARTICLES OF Foon. 
