CONTENTS XV 



c. Cross reactivation 362 



d. Effects of ultraviolet light on genetic recom- 

 bination 363 



XIX Lysogeny F. Jacob and E.-L. Wollman 365 



1. Definition and occurrence 365 



2. Prophage 366 



3. Properties of temperate phages 369 



4. Lysogenization 370 



5. Production of phage by lysogenic bacteria 371 



a. Spontaneous production 371 



b. Induction 372 



6. Immunity 374 



7. Defective lysogenic bacteria 375 



8. Lysogeny and bacterial genetics 376 



a. Transduction 377 



b. Changes in the bacterium resulting from 

 lysogenization 378 



9. Conclusion 379 



XX Colicins and Other Bacteriocins 



F. Jacob and E.-L. Wollman 381 



1 . Definition and criteria 381 



a. Definition 381 



b. Detection and titration 382 



c. Physicochemical properties 384 



2. Action of colicins on sensitive bacteria 385 



a. Specificity 385 



b. Mode of action 386 



3. Colicinogenic bacteria 387 



a. Production of colicin 388 



b. Genetic determination of colicinogeny 389 



4. Other bacteriocins 390 



5. Bacteriocins and bacteriophages 392 



XXI Use of Phages in Epidemiological Studies 



E. S. Anderson 395 



1 . Historical 397 



2. The Vi-phage typing scheme of Craigie and Yen. . 399 



3. Technical considerations 402 



a. Isolation of phages for typing purposes 402 



b. The routine test dilution 403 



c. Technique 404 



