LONDON.Royal Society, February 15.—Sir Archibald Geikie, K.C.B., president, in the chair.—Dr. T. Graham Brown: An alleged specific instance of the transmission of acquired characters—investigation and criticism. An examination of the “Brown-Séquard phenomenon” in guinea-pigs—usually considered to be a classical instance of the alleged transmission of an acquired character—throws much do,ubt upon its value in this controversy. The phenomenon is not an acquired peculiarity produced de novo on division of a great sciatic nerve. It is due to the raised excitability of a mechanism—that of the scratch-reflex—already present; and this raised excitability is probably due to the removal of an inhibiting influence by section of the nerve. The phenomenon, therefore, cannot be considered as transmissible as an acquirement per se. If anything is transmitted as an acquired character, it must be the state of raised excitability of the scratch-reflex. The presence of the phenomenon in the offspring observed by Brown-Séquard may be admitted, but this may be explained otherwise than by assuming a transmission of acquired characteristics. That the alternative explanation-the presence in the offspring is due to a production of the state by injury to the toes and feet inflicted by the parent—is true is rendered possible, and indeed highly probable, by certain parallel evidence submitted in this paper.—W. B. Alexander: Further experiments on the cross-breeding of two races of the moth, Acidalia virgularia. This, paper deals with the descendants of some of the moths of this species reared by Messrs. Prout and Bacot, who read a paper on their results to the Royal Society on February 25, 1909. They did not arrive at any definite conclusions in regard to the process of heredity followed. The author agrees with them in finding that Acidalia virgularia and its variety canteneraria are not two Mendelian forms of the species, though he finds that one of the differences between the two forms, namely, the presence of black speckling on the wings of A. virgularia, is inherited according to Mendel's law.—F. H. A. Marshall: The effects of castration and ovariotomy upon sheep. (1) The development of horns in the males of a breed of sheep in which well-marked secondary sexual differentiation occurs (as manifested especially by presence or absence of horns) depends upon a stimulus arising in the testes, and this stimulus is essential not merely for the initiation of the horn-growth, but for its continuance, the horns ceasing to grow whenever the testes are removed. (2) The removal of the ovaries from young ewes belonging to such a breed does not lead to the development of horns or definitely male characters, except possibly in a very minor degree.—Dr. T. L. Lewellyn: The causes and prevention of miners' nystagmus. Miners' nystagmus is an occupational neurosis confined to coal miners. It is characterised by a rotatory oscillation of the eyes, and produces a disability which is marked and prolonged in severe cases. One thousand six hundred and eighteen cases received compensation in the United Kingdom in 1911. Pathologically the complaint appears to be a condition of imperfect centripetal impulses (imperfect fixation, disturbance of equilibrium, &c), the intimate connection between the centres governing the associated movements of the eyes being lost, and incoordinate movements ensuing. The principal preventive measures indicated are improvement of illumination, elimination of unfit workers by medical examination, and employment of coal-cutters in thin seams.—W. Lawrence Balls: The stomatograph. The stomatograph is a self-recording instrument adapted from Mr. Francis Darwin's porometer (see NATURE, August 10, 1911). A five days' record of the opening and closing of the stomata of the cotton plant in Egypt is given, showing the stomata wide open during bright sunshine. The author has elsewhere shown that during this part of the day no growth occurs, and there is evidence that the apparent waste of water then occurring is of importance as keeping the leaves col, since when transpiration is artificially checked the leaves are rapidly injured or even killed by the high temperature.-G. A. Buckipaster and J. A. Gardner: The composition of the blood gases during the respiration of oxygen. A number of analyses were made of the blood of cats respiring (1) air, (2) oxygen for periods of one to two hours. The average composition in c.c. per 100 c.c. of arterial blood for cats breathing air was as follows (mean of thirteen experiments):-Total gas, 5376; CO, 38·43; O2, 14·22; N, 1·12. The percentage saturation of haemoglobin with oxygen was 83. For cats breathing oxygen the mean values by thirteen experiments were as follows:-Total gas, 53·79; CO2, 38·65; O., 14·93; N, 0·16. The average percentage saturation of haemoglobin with oxygen was 89·6. From their experiments the authors conclude that the inhalation of oxygen does not materially augment either the quantity of this gas or the quantity of carbon-dioxide in the blood.