Continuous Culture of Some Anerobic and Facultatively Anaerobic Rumen Bacteria.

PAQE Continuous Culture of Rumen Bacteria: Apparatus BY P. N. HOBSON . . . . . . 161 Continuous Culture of Some Anaerobic and Facultatively Anaerobic Rumen Bacteria BY P.N. HOBSON . . . . . . . . . . . . . . . . . 167 The Behaviour of Tanned Erythrocytes in Various Haemagglutination Systems BY G. A. GARABEDIAN 181 Modified Degrees of Streptomycin-Dependence and Resistance in Escherichia coli BY G. E. P~umam 189 The Virulence of Biochemical Variants of Streptococcus pyogenes BY N. CROWLEY . . . . 197 Kinetics of the Potassiumand Sodium-Activated Infection of a Transforming Deoxyribonucleic Acid in Pneumococcus BY M. KOHOUTOVA . . . . . . . . . . 211 Glyconeogenesis in Growing and Non-growing Cultures of Telrahymena pyriformmis BY M. R. LEVY and 0. H. SCHERBAUM . . . . . . . . . . . . . . 221 Effect of Ultraviolet Radiation and the Induction of Vegetative Reproduction of Phage Lambda on the Ultracentrifuge Pattern of Extracts of Escherichia coli BY B. A. FRY and J. SYKES . 281 The Base Composition of Deoxyribonucleic Acids of Streptomyces BY C. FRONTALI, . R. HILL and L. G. SILVESTRI . . . . . . . . . . . . . . . 248 Use of Antibiotics for Selective Isolation and Enumeration of Actinomycetes in Soil BY S. T. WILLIAMS and F. L. DAVIES . . . . . . . . . . . . . 251 Determination of Kinetic Constants for Nitrifying Bacteria in Mixed Culture, with the Aid of an Electronic Computer BY G. KNOWLES, A. L. DOWNING and M. J. BARRETT . . . . 268 The Differentiation of Streptococcus faecalis and S. faecium BY R. WHITTENBURY . . . . 279 Spore Surface Depsipeptides in Some Pithomyces Species BY E. BISHOP, H. GRIFFITES, D. W. RUSSELL, V. WARD and R. N. GARTSIDE . . . . . . . . . . . 289 .