Modes of resistance to benzylpenicillin and ampicillin in twelve Klebsiella strains.

Composition of Cell Walls of Some Gram-Negative Cocci BY R. K. GRAHAM and J. W. MAY . Electron Microscopy Studies on the Immobilization Antigens of Paramecium aurelia BY M. R. Mom A Note on the Taxonomic Status of Strains Like ‘Campo’ Hitherto Classified as Mycoplasma hominis Type 2 BY D. G. FT. EDWARD and E. A. FREUNDT . . . . . . . . . The Influence of Temperature and pH Value on the Macromolecular Composition of Magnesiumlimited and Glycerol-limited Aerobacter aerogenes Growing in a Chemostat BY D. W. TEMPEST a n d J . R . H m R . . . . . . . . . . . . . . . 267 The Fine Structure of Sporangia of Phylophthma erythroseptica. BY J. A. CHAPMAN and R. V U J I ~ I I ~ 275 Studies on the Haemagglutinin Present in Cossackie A7 Virus-Infected Suckling Mouse Tissue BY . J. D. WILLIAMSON and N. R. GRIST . . . . . . . . . 2 8 8 d