Cracow. Polish Academy of Science and Letters, May 4.—I. Neyman and E. S. Pearson: The problem of k samples.—W. Goslawski and L. Marchlewski: The absorption of ultra-violet radiations by certain organic substances.—K. Dziewonski and St. Pizoń: A new method of synthesis of dinaphthopyrone. Dibenzox-anthone can be obtained directly by the interaction of β-naphthol and carbanilide or thiocarbanilide.—Mlle. Bron. Mlodzianowska: The earliest stages of the development of Cysticercus fasciolaris of the larva of Taenia taeniaeformis.—S. Skowron and T. Pawlas: Observations on the influence of gonacrine on the organism.