Theory of the Gene 1
Goldschmidt,Richard B．Chromosomes and genes 1
McClintock,Barbara．Chromosome organization and genic expression 13
Stadler,L．J．Spontaneous mutation in maize 49
Horowitz,N．H．,and Leupold,Urs．Some recent studies bearing on the one gene-one enzyme hypothesis 65
Cytoplasmic Constituents of Heredity 75
Ephrussi,Boris,and Hottinguer,Helene．On an unstable cell state in yeast 75
Spiegelman,S．The particulate transmission of enzyme-forming capacity in yeast 87
L＇ Heritier,Ph．The Co2 Sensitivity problem in Drosophila 99
Provasoli,Luigi,Hutner,S．H．,and Pintner,Irma J．Destruction of chloroplasts by streptomycin 113
Michaelis,P．Interactions between genes and cytoplasm in Epilobium 121
Evolution of the Gene 131
Stephens,S．G．＂Homologous＂genetic loci in Gossypium 131
Bonner,David M．Gene-enzyme relationships in Neurospora 143
Lewis,E．B．Pseudoallelism and gene evolution 159
Schultz,Jack,and Redfield,Helen．Interchromosomal effects on crossing over in Drosophila 175
Induction of Changes in Genes and Chromosomes Ⅰ 199
Auerbach,Charlotte．Problems in chemical mutagensis 199
Demerec,M．,and Hanson,Jessie．Mutagenic action of manganous chloride 215
Roberts,Richard B．,and Aldous,Elaine．Manganese metabolism of Escherichia coli as related to its mutagenic action 229
Levan,Albert．Chemically induced chromosome reactions in Allium cepa and Vicia faba 233
Jensen,K．A．,Kirk,I．,Kolmark,G．,and Westergaard,M．Chemically induced mutations in Neurospora 245
Induction of Changes in Genes and Chromosomes Ⅱ 263
Gustafsson,Ake．Mutations,environment and evolution 263
Giles,Norman H．,Jr．Studies on the mechanism of reversion in biochemical mutants of Neurospora crassa 283
Hollaender,Alexander,Baker,W．K．,and Anderson,E．H．Effect of oxygen tension and certain chemicals on the X-ray sensitivity of mutation production and survival 315
Russell,W．L．X-ray induced mutations in mice 327
Genetic Mechanisms in Bacteria and Bacterial Viruses Ⅰ 337
Novick,Aaron,and Szilard,Leo．Experiments on spontaneous and chemically induced mutations of bacteria growing in the chemostat 337
Atwood,K．C．,Schneider,Lillian K．,and Ryan,Francis J．Selective mechanisms in basteda 345
Witkin,Evelyn,M．Nuclear segregation and the delayed appearance of induced mutants in Escherichia coli 357
Genetic Mechanisms in Bacteria and Bacterial Viruses Ⅱ 373
Bisset,K．A．Genetical implications of bacterial cytology 376
DeLamater,Edward D．A new cytological basis for bacterial genetics 381
Lederberg,J．,Lederberg,E．M．,Zinder,N．D．,and Lively,E．R．Recombination analysis of bacterial heredity 413
Genetic mechanisms in Bacteria and Bacterial Viruses Ⅲ 445
Ephrussi-Taylor,Harriett．Genetic aspects of transformations of pneumococci 445
Hotchkiss,Rollin D．Transfer of penicillin resistance in pneumococci by the desoxyribonucleate derived from resistant cultures 457
Luria,S．E．The frequency distribution of spontaneous bacteriophage mutants as evidence for the exponential rate of phage reproduction 463
Hershey,A．D．,and Chase,Martha．Genetic recombination and heterozygosis in bacteriophage 471
Concluding Session 481
Mirsky,A．E．Some enzymes of isolated nuclei 481
Sonneborn,T．M．Some current problems of genetics in the light of investigations on Chlamydomonas and Paramecium 483
Appendix 505
Flory,L．E．The television microscope 505