LONDON. Royal Society, December 11.—Sir J. J. Thomson, president, in the chair.—C. F. U. Meek: A further study of chromosome dimensions. The degree of somatic complexity of an animal cannot be correlated with (a) the lengths of the chromosomes composing its complex; (b) the diameters of the chromosomes composing its complex; (c) the total volume of the chromosomes composing its complex; and (d) the number of the chromosomes composing its complex. There are many different chromosome diameters. The chromosomes composing the spermatogonial complex of an animal are not necessarily identical in diameter with those composing its secondary spermato-cyte complex. All chromosomes composing an individual complex are not necessarily of the same diameter.—J. M. H. Campbell, C. Q. Douglas, and F. G. Hobson: The respiratory exchange of man during and after muscular exercise. Support is given to the view that muscular work may involve the metabolism of a higher proportion of carbohydrate to fat than is the case during rest. In the case of the severer degrees of work, serious shortage of oxygen, as indicated by the production of lactic acid, may lead in the earlier stages of the exercise to temporary great exaggeration of the hyperpncea, accompanied by washing out of preformed CO2 from the body and ah abnormally high respiratory quotient, phenomena which are absent in the case of lighter work.—A. D. Waller: The energv output of dock labourers during heavy work. Part i. The paper contains the results of observations on dock labourers by a simplified method, which consists in measurements of the CO3 discharge at convenient intervals throughout the working day or night with the least possible interruption of work.—J. Gray: The relation of spermatozoa to certain electrolytes (ii.). The paper embodies an attempt to apply the facts of recent chemistry to the behaviour of the living cell.