The formation and germination of microcysts in Myxococcus xanthus.

CON TENT S Fimbriae and Haemagglutinating Activity in Strains of Protezcs humeri BY W. I. H. SHEDDEN . Aberrant Forms of Mycobacterium phlei Produccd by Streptomycin and thcir Multiplication on Streptomycin-frec Media BY S. E. JUHASZ . . . . . . . . . . Rate of Growth of Bacillus cereus between Divisicns BY J. I?. COLLINS and M. H. RICHMOND. . Chemical Composition and Antigenic Structure of Cell Walls of Coynebacterium, Mycobuctmhn, Nocardia, Actinomyces and Arthrobacter RY (1'. S. CUMM~NS . . . . . . . Electron Microscope Observations on the Structure of Fimbriae, with Particular Reference t o Klebsiella Strains, by the use of the Negative Staining Technique BY M. J. THORNLEY and R. W. HORNE . . . . . . . . . . . . . . . . Sulphydryl Metabolism of Fungi Grown in Submerged Culture BY J. E. ROBSON and H. M. STOCKLEY The Infrared Spectra of Some Acetic Acid Bacteria BY A. W. SCOPES 2 . . . . . The Formation and Germination of Microcysts in Myxococcus xanthus BY M. DWORKIN and H. V O E L Z , . . . . . . . . . . . . . . . . The Pathogenicity of Bacillus anthracis Lysogenic with Mutants of Phage W BY G. IVANOVICS . Characters of a Group of Bacillus phages BY E. \V. MEYNELL . . . . . . Enumeration of Rumen Micro-organisms BY A. I:. I. WARNER . . . . . . . Some Factors Influencing the Rumen Microbial Population BY A. C. I. WARNER . . . . Effect of Biotin-Sparing Substances on Growth I )f Biotin-Deficient Succharmngces cerevisiae and on the Synthesis of Kucleic Acids and Protein BY FAZAL AEIMAD and A. €1. ROSE . . . Evidence for a Flavoprotein Photoreceptor in Phycomyces BY M. J. CARLILE . . . . . Salnionalla enteridif is as a Genetic Donor in Iritraspecific and Interspecific Crosses Initiated by Colicine Factors BY G. G. MEYNELL . . . . . . . . . . . . Absence of the Group-specific and the Cell-wall Polysaccharide Antigcn in L-phase Variants of Group D Streptococci BY W. HIJMANS . . . . . . . . , . . Indifferent and Haemolytic Streptococci Posscssing Group-Antigen F BY 13. OTTENS and I<. C. WINKLER . . . . . . . . . . . . . . . . . PAGE