LONDON. Royal Society, Mar. 13.—V. B. Wigglesworth: A theory of tracheal respiration in insects. The theory provides for the increased demands for oxygen which arise locally in active tissues. If it be assumed that the terminal portions of the tracheal tubes are bounded by a semi-permeable membrane, then liquid will be drawn up the tubes by capillarity until further progress is checked by osmotic pressure of the tissue fluids. During activity lactic acid will be produced, osmotic pressure will rise, liquid will be absorbed, and air will extend down the tubes towards the active tissues. The theory is supported by experiments on mosquito larv (see NATURE, Dec. 28, 1929, p. 986). Some observations are recorded on the effects of certain poisonous gases and of oil on the tracheal system. H. Raistrick and others: Studies in the biochemistry of the lower fungi. A resume of the main results of investigations presented in eighteen papers communicated to the Society.