This journal provides immediate access to some articles. Volume 12(1); January 1926 Chemistry The Density and Atomic Weight of Helium: II PMCID: PMC1084391 Genetics The Direct Results of Mendelian Segregation PMCID: PMC1084387 On the Attachment of Non-Homologous Chromosomes at the Reduction Division in Certain 25-Chromosome Daturas PMCID: PMC1084388 Reddish—A Frequently “Mutating” Character in Drosophila Virilis PMCID: PMC1084389 The Explanation of Hybrid Vigor PMCID: PMC1084390 Mathematics On Normal Coördinates in the Geometry of Paths PMCID: PMC1084399 A Simple Derivation of Kronecker's Relation among the Minors of a Symmetric Determinant PMCID: PMC1084400 Physics The Nature of Light PMCID: PMC1084392 The Rôle of the Faraday Cylinder in the Measurement of Electron Currents PMCID: PMC1084393 The Quantum Theory of the Dielectric Constant of Hydrogen Chloride and Similar Gases PMCID: PMC1084394 The Mobility of Gaseous Ions in HCl Gas and HCl Air Mixtures PMCID: PMC1084395 The Mobility of Gas Ions in HCl Mixtures and the Nature of the Ion PMCID: PMC1084396 High Frequency Rays of Cosmic Origin PMCID: PMC1084397 The Joule-Thomson Effect in Air PMCID: PMC1084398 Correction The Effect of Varying Mass on a Binary System PMCID: PMC1084386 Corrects: The Frequency Distribution of Some Measured Parallaxes and of the Parallaxes Themselves. Proc Natl Acad Sci U S A. 1925 May; 11(5): 270–274. Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||