viii CONTENTS 



CHAPTER PAGE 



XX. Synthetic Culture Media 279 



H. W. Schocnlein 



XXI. Determinations of Thermal Death-Time 285 



/. Russell Esty 

 XXII. The Standardization of Disinfectants and Antiseptics . . . 301 

 George F. Reddish 



XXIII. Nature, Distribution, AND Functions OF Soil Micro-organisms . 310 



Selman A . Wakstnan 



XXIV. Autotrophic Bacteria 322 



Robert L. Star key 

 XXV. The Root-Nodule Bacteria of Leguminous Plants . . . -332 

 • Edwin Broun Fred 



XXVI. Micro-organisms in Relation to Soil Fertility 341 



Jacob G. Lipman 

 XXVII. The Role of Bacteria in the Treatment of Sewage . . . -351 

 F. W. Mohlman 



XXVIII. Some Problems in Water Bacteriology 362 



John F. Norton 

 XXIX. The Action of Ultra- Violet Light on Bacteria AND Their Products 371 

 Johfi F. Norton 



XXX. Bacteria in Milk 378 



Robert S. Breed 



XXXI. Bacteria in Dairy Products 395 



L. A. Rogers 

 XXXII. The Bacterial and Health Aspects of Pasteurization . . . 403 

 Milton J. Rosenau 



XXXIII. Mechanical and Engineering Aspects of Pasteurization . . . 419 



George W. Putnam 



XXXIV. Contamination and Deterioration of Food 437 



Charles Thorn 



XXXV. The Bacteria of Food Poisoning 443 



Edwin 0. Jordan 



XXXVI. The Spirochetes 452 



Hideyo Noguchi 



XXXVII. Current Problems on Yeasts 498 



F. W. Tanner 



XXXVIII. The Aspergilli: A Typical Group of Molds 509 



Charles Thorn 



XXXIX. FiLTEElABLE VIRUSES 5^7 



Thomas M. Rivers 

 XL. The Bacteriophage: Present Status of the Question of Its Nature 



AND Mode of Action 525 



J. Bronfenbrenner 



XLI. Filterability of Micro-organisms 557 



5". P. Kramer 



XLII. A Theory of Microbic Virulence 565 



/. S. Falk 



