This journal provides immediate access to some articles. Volume 8(2); February 1922 Genetics Structural Changes Associated with Factor Mutations and with Chromosome Mutations in Datura PMCID: PMC1084951 Mathematics The Riemann Geometry and Its Generalization PMCID: PMC1084952 Ricci's Principal Directions for a Riemann Space and the Einstein Theory PMCID: PMC1084953 Note on the Definition of a Lineal Functional PMCID: PMC1084954 Zoölogy Skin Transplantation in Frog Tadpoles PMCID: PMC1084955 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||