CONTENTS Xlll 



3. Partial metabolic requirements for vegetative 

 replication 247 



4. Sources of material for phage synthesis 248 



a. Materials derived from the parental phage . 249 



b. Protein materials assimilated before and after 

 infection 249 



c. Nucleic acid materials assimilated before and 

 after infection 254 



5. Kinetic studies of DNA metabolism 257 



6. Summary 262 



XV Chemical Interference with Phage Growth J.S.GoTS 265 



1 . Prevention of adsorption 267 



2. Prevention of penetration 270 



3. Inhibition at the intracellular level 271 



a. Interference with energy metabolism 272 



b. Prevention of protein synthesis 273 



c. Prevention of DNA synthesis as a conse- 

 quence of protein deficiency 275 



d. Prevention of DNA synthesis 276 



e. Prevention of coenzyme activity 276 



f. Prevention of maturation 278 



4. Abortive infection 282 



5. Noninfective phage particles containing structural 

 analogues 283 



6. Miscellaneous inhibitors 284 



a. Antibiotics 284 



b. Aromatic diamidines 285 



c. Dyestuffs 286 



7. Summary 286 



XVI Mutation and Phenotypic Variation in Phages 289 



1 . Definitions 290 



2. Nonhereditary (phenotypic) variation 291 



a. Host-induced modifications 291 



b. Phenocopies 294 



c. Phenotypic mixing 294 



d. Other phenotypic modifications 296 



3. Hereditary variation (mutation) 297 



a. Mutations affecting specificity of adsorption 298 



b. Mutations afi"ecting growth potential 299 



