On a Problem of Formal Logic -- Non-Separable and Planar Graphs* -- A Combinatorial Problem in Geometry -- On Representatives of Subsets -- On the Abstract Properties of Linear Dependence1 -- The Dissection of Rectangles Into Squares -- On Colouring the Nodes of a Network -- Solution of the "Problème Des Ménages" -- A Ring in Graph Theory -- A Decomposition Theorem for Partially Ordered Sets -- The Marriage Problem* -- Circuits and Trees in Oriented Linear Graphs -- The Factors of Graphs -- A Partition Calculus in Set Theory -- Maximal Flow Through a Network -- On Picture-Writing* -- A Theorem on Flows in Networks -- Combinatorial Properties of Matrices of Zeros and Ones -- Graph Theory and Probability -- The Statistics of Dimers on a Lattice -- Longest Increasing and Decreasing Subsequences -- On a Theorem of R. Jungen -- Regularity and Positional Games -- On Well-Quasi-Ordering Finite Trees -- On the Foundations of Combinatorial Theory -- Paths, Trees, and Flowers -- A Theorem of Finite Sets -- A Short Proof of Sperner's Lemma -- Möbius Inversion in Lattices -- A Generalization of a Combinatorial Theorem of Macaulay -- Short Proof of a Conjecture by Dyson -- On a Lemma of Littlewood and Offord on the Distributions of Linear Combinations of Vectors* -- Ramsey's Theorem for a Class of Categories -- A Characterization of Perfect Graphs -- A Note on the Line Reconstruction Problem -- Acyclic Orientations of Graphs* -- Valuations on Distributive Lattices I -- Valuations on Distributive Lattices II -- Valuations on Distributive Lattices III.