This journal provides immediate access to some articles. Volume 28(6); June 1942 Biochemistry The Dissociation Constant in Nitrogen Fixation by Azotobacter PMCID: PMC1078457 Botany The Release of Auxin from Isolated Leaf Proteins of Spinach by Enzymes PMCID: PMC1078454 Genetics The Distribution of X-Ray Induced Chromosomal Aberrations PMCID: PMC1078455 Genetic Control of Biochemical Reactions in Neurospora: An “Aminobenzoicless” Mutant PMCID: PMC1078456 Mathematics Some Deductions from Frobenius's Theorem PMCID: PMC1078458 On Monothetic Groups PMCID: PMC1078459 On the Dirichlet Problem for the Hyperbolic Case PMCID: PMC1078460 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||