This journal provides immediate access to some articles. Volume 9(3); March 1923 Bacteriology The Mechanism of Selective Bacteriostasis PMCID: PMC1085270 Botany A Note on the Statistics of Cyclic Growth PMCID: PMC1085265 Chemistry Compressibility, Internal Pressure and Atomic Magnitudes PMCID: PMC1085268 The Separation of Isotopes PMCID: PMC1085269 An Investigation of the Chemical Nature of Two Typical Enzymes: Pancreatic and Malt Amylases PMCID: PMC1085271 Mathematics Continuous Transformations of Manifolds PMCID: PMC1085273 A Lemma on Systems of Knotted Curves PMCID: PMC1085274 Physics Stokes' Law of Fall Completely Corrected PMCID: PMC1085266 Gaseous Viscosity Measured by the Interferometer U-Tube PMCID: PMC1085267 Statistics Note on the Relative Abundance of the Elements in the Earth's Crust PMCID: PMC1085272 Zoölogy The Nerve Net in the Earthworm: Preliminary Report PMCID: PMC1085275 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||