The formation of a starch-like polysaccharide from maltose by strains of Streptococcus pyogenes.

Natural Selection in the Microbial World. The Second Marjory Stephenson Memorial . . . . . . . . . . . . . Lecture. By C. B. VAN NIEL The Action of Streptococcal Amylase in relation to the Synthesis of an Amylosaccharide by Amylolytic Strains of Streptococcus pyogenes. By N . CROWLEY . . . . . The Formation of a Starch-like Polysaccharide from Maltose by Strains of Streptococcus . . . . . . . . . . pyogenes. By N. CROWLEY and hl. P. JEVONS Tricarboxylic Acid Cycle Reactions in the Fungus Zygorrhynchus moelleri. By V . MOSES . Studies on a Soap Tolerant Organism : a New Variety of Bacterium anitratum. By E. BILLING Commensalism in Pathogenic Anaerobic Actinomyces Cultures. By D. ERIKSON and J. W. . . . . . . . . . . . . . . . . . PORTEOUS A Partially Defined Culture Medium for Trypanosoma cruzi and some other Haemoflagellates. By N. CITRI and N . G ~ o s s o w ~ c z . . . . . . . . . . . The Preferential Synthesis of /)-Galactosidase in Escherichia coli. By H. V . RICKENBERG . . . . . . . . . . . . . . . . and G. LESTER Larnpropedia hyalina Schroeter 1886 and Vannielia aggregata n.g., n.sp., with Remarks on Natural and on Organized Colonies in Bacteria. By E. G. PRINGSHEIM . . . . The Morphology and Relationships of 'Lactobaccillus' bifidzrs. By A. C . HAYWARD, C. M. F. HALE and K. A. BISSET . . . . . . . . . . . . . . 'Fruity' and other Mutants of the Cellular Slime Mould, Dictyostelium discoideum : a Study of Developmental Aberrations. By M. SUSSMAN . . . . . . . . . The Electron-dense Bodies of Mycobacterium phlei. By A. M . GLAUERT and E. M. BRIEGER . Cytological Studies of Nuclear Division in Salmonella typhimurium. By K . G. LARK, 0. MAALP~E and 0. ROSTOCK . . . . . . . . . . . . . . Reconstruction of the Nuclear Sites of Salmonella typhimurium from Electron Micro. . . . . . . . graphs of Serial Sections. By A. BIRCH-ANDERSEN The Effects of Metaperiodate and Heated Influenza Virus on Influenza Virus Growth. By I. ARCHETTI, H. B. DONALD, A. ISAACS and R. C. VALENTINE . . . . . . . Pigment Production by Staphylococci. By M. BARBER . . . . . . . . . . . . . . . Recombination with Herpes Simplex Virus. By P. WILDY Beta-oxidation of Fatty Acids by Nocardia opaca. By D. M . WEBLEY, R. B. DUFF and V. C. . . . . . . . . . . . . . . . . . FARMER Studies on the Ability of Light to Counteract the Inactivating Action of Ultraviolet Radiation on Plant Viruses. By F. C. BAWDEN and A. KLECZKOWSKI . . . . . . . . . . The Action of Fibrinogen on certain Pathogenic Cocci. By E. S. DUTHIE The Development of the 'Straight Rod Type' of Lactobacillus bifidus. By H . G. GYLLENBERG