This journal provides immediate access to some articles. Volume 30(2); February 15, 1944 Mathematics Relative Number of Non-Invariant Operators in a Group PMCID: PMC1078660 Note on the Function F(a, b; c — n; z) PMCID: PMC1078661 Pathology and Bacteriology A Second Approximation to Soper's Epidemic Curve PMCID: PMC1078663 Physiology and Biochemistry Indole and Serine in the Biosynthesis and Breakdown of Tryptophane PMCID: PMC1078662 Corrections An Orthogonal Property of the Hypergeometric Polynomial PMCID: PMC1078664 Corrects: An Orthogonal Property of the Hypergeometric Polynomial. Proc Natl Acad Sci U S A. 1942 September; 28(9): 374–377. Some Asymptotic Relations PMCID: PMC1078665 Corrects: Some Asymptotic Relations. Proc Natl Acad Sci U S A. 1942 September; 28(9): 371–374. | ||