This journal provides immediate access to some articles. Volume 4(4); April 1918 Botany Dynamical Aspects of Photosynthesis PMCID: PMC1091408 National Research Council Minutes of Executive Board of War Organization PMCID: PMC1091415 Petrology A Contribution to the Petrography of the South Sea Islands PMCID: PMC1091413 Physics Mobilities of Ions in Air, Hydrogen, and Nitrogen PMCID: PMC1091409 Thermo-Electric Action with Dual Conduction of Electricity PMCID: PMC1091410 Terrestrial Temperature and Atmospheric Absorption PMCID: PMC1091411 Mobilities of Ions in Vapors PMCID: PMC1091412 Physiology The Law Controlling the Quantity and Rate of Regeneration PMCID: PMC1091414 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||