This journal provides immediate access to some articles. Volume 19(7); July 1933 Astronomy On the Interpretation of Nova Spectra PMCID: PMC1086128 Genetics Chromosome Number and Morphology in Nicotiana VI: Chromosome Numbers of Forty Species PMCID: PMC1086129 Geology Young's Modulus and Poisson's Ratio with Reference to Geophysical Applications PMCID: PMC1086130 Compressibility and Anisotropy of Rocks at and near the Earth's Surface PMCID: PMC1086131 Comparison of the Statically and Seismologically Determined Elastic Constants of Rocks PMCID: PMC1086132 Mathematics The General Case of Non-Homogeneous Linear Differential Equations PMCID: PMC1086133 A Canonical Form for a Set of Vectors PMCID: PMC1086134 On a Theorem of Fejér PMCID: PMC1086135 Paleontology Aristogenesis, the Observed Order of Biomechanical Evolution PMCID: PMC1086136 Pathology Electrosmosis and Anomalous Osmosis PMCID: PMC1086137 Physics Note on the Sturm-Liouville Eigenvalue-Eigenfunction Problem with Singular End-Points PMCID: PMC1086138 Physiology Studies on the Growth Hormone of Plants: III. The Inhibiting Action of the Growth Substance on Bud Development PMCID: PMC1086139 Studies on the Growth Hormone of Plants: IV. On the Mechanism of the Action PMCID: PMC1086140 The Energy of Urea Synthesis: II. The Effect of Varying Hydrogen Ion Concentration with Different Metabolites PMCID: PMC1086141 On the Temperature-Regulatory Function of “Spontaneous” Activity in the Mouse PMCID: PMC1086142 The Development of Temperature Regulation in the Mouse PMCID: PMC1086143 Psychology The Influence of Use or Frequency of Occurrence upon the Strength of Mental Connections PMCID: PMC1086144 Zoölogy The Effects of the Pituitary Hormones on the Melanophores of Fishes PMCID: PMC1086145 The Occurrence of Guanophores in Fundulus PMCID: PMC1086146 Photic Stimulation and Rhythmical Contractions of the Mantle Flaps of a Lamellibranch PMCID: PMC1086147 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||